Two months ago, I wrote about Remember The Milk, which keeps track of all things I should do. I also started to use Evernote, where I can put all things I should remember. By making that distinction, these two services are perfectly capable of complementing each other.

In essence, Evernote is a note taking application. It started as an offline application for both Windows and Mac OS X, but since online synchronization came into play it's more like a web service. It has a web interface, official clients for Windows, Android, Mac OS X and a whole bunch of other mobile devices (check their Downloads page to see the list). There are also browser extensions for Chrome and Firefox, to "clip" certain content directly to your Evernote account. In other words, Evernote is never far away and it's easy to capture everything you see or think of at that moment.

A nice thing is that Evernote has no storage limit, you can store as much as you want. However, there's a monthly upload limit which resets every month. Free accounts can upload 60 MB each month, which is good for thousands of text notes or a bunch of pictures and audio clips. You can attach files to your notes, but the file size is limited to 25 MB and only a limited number of file types are allowed. Premium accounts can upload no less than 1 GB each month, and can attach files of any type to a note with a maximum of 50 MB. The great thing is that these files are indexed: texts are extracted from images (and these images don't have to be of high quality to make it work), and PDF's become searchable.

You can create notebooks to put your notes into, one for work and one for personal things, for example. You can also tag your notes. This makes searching easier when you end up with hundreds or even thousands of notes, you can choose to only search notes in a particular notebook and having a particular tag. Evernote creates little thumbnails of your notes, which makes it easy to recognize the note you are looking for in the search results.

An additional service you get when you opt for the paid subscription is the note history. Several times a day, Evernote makes a snapshot of all notes (only when a note has changed in the meantime). You can browse all older versions of your notes and restore them if you want to. This comes in handy when you regret deleting some content from your notes.

Here follows a list of the Evernote clients I use, almost all of them on a daily basis.

Web

The web interface is probably the weakest link of the service, it feels outdated and sometimes it gets a bit buggy, especially when you're dealing with large notes, or when dealing with formatting (alignment, indentation, lists). The editor has an auto-save feature, which may cause the text editor to jump to the top of the text while typing. Also it misses some features which are available in the Windows client, such as text encryption and making tables. Still, the web interface is functional and allows you to access your notes from anywhere. I hope this will be addressed this year, to make the site a smoother experience.

Chrome extension

The Chrome extension allows you to save bookmarks or save entire web pages to your Evernote account. If you want to bookmark a URL you can summon the web clipper and enter some more fields with tags and personal notes if you like. You can also choose to save the full page (or just the selection) with all images and formatting to your note. This will come in handy when the text suddenly disappears from the web, in that case you still have your own copy. The Chrome extension also offers the option to search your Evernote account simultaneously whenever you perform a search on Google, but I wrote before that I am not completely comfortable with that option.

Windows client (4.2.2.3900)

The Windows client is quite OK, it makes working with Evernote easier than with the web interface. There's an Evernote icon in the system tray which offers some options to create notes from clipboard content or screenshots. As I wrote earlier, the editor provides somewhat more options and is more usable than on the web. However, it's strange that subscript and superscript are missing in the editor, while this is possible in the web interface. Also, editing bulleted lists is just as painful as in the web interface, especially when dealing with multiline items or nested lists.
You can also choose to encrypt certain content if you don't want certain information to end up on the Evernote server as plain text. This content is encrypted with a single password (which shouldn't be the same as your Evernote account password). And of course that password is not transmitted. All interfaces (as far as I know) can decrypt these portions by entering your password again. The Mac client also supports encryption.
While the Windows client is not too bad to work with, it may become a bit buggy. Especially when you are dealing with larger notes, the client may become slow (or even unresponsive). Also, I noticed that writing a note in a separate window for a little while seems to cause some corruption on the screen (for instance the toolbars go black). In these circumstances, I have to restart Evernote to continue normally.

Android client (2.6.1)

The Android client is decent (version 2.0 and above). It shows the notes fine and it's able to store some notebooks on your SD card for offline reference. It provides fast access to everything I need to remember. You can choose whether you'd like to synchronize your notes in the background and how often that should happen. If you store many attachments in Evernote, it may be wise to sync only when connected to a wireless network.
In a draft version of this text I mentioned a few issues with the Android client, but amazingly they have been resolved in the meantime. There's nothing negative to say about the app as far as I can think of.

Nevernote (Java)

Being both an Evernote user and a Linux user is a bit unfortunate, since there is no official client for Linux. The web interface is at your disposal, but as I wrote above it's a bit clunky and not very convenient to work with. However, there's a third party client which cooperates with Evernote fairly well, called Nevernote.
This Java application works quite OK and even offers some features which are nowhere to be found in the official Evernote interfaces (such as background colors for text).
Still I stopped using it because I didn't feel very comfortable with it. More often than I wanted it showed me a warning that it lost some note attachments. I decided not to await data loss due to a messed up synchronization with this client and decided to wait for a better web interface (my guts tell me it shouldn't take that long for it to appear). Also, being a Java program, it doesn't integrate well with my window manager and invoking other applications with it (web browser, PDF reader) wasn't quite good. I am very well aware these last points of critique are not Nevernote's fault and it's partly my own laziness not to investigate these issues myself. (However, the developer could have 'helped' to use C++/Qt instead of Java ). Still, the uncomfortable feeling with the 'missing data' warnings was the main reason.

How I use Evernote

I believe it's fairly traditional to describe your personal workflow with Evernote when you spend a blog entry on this service, so here we go. I have three stacks of notebooks: one for study, one for work and one for personal stuff. Each stack consists of four notebooks:

• Bookmarks - Here I store links to interesting websites, sometimes with a short note to describe the website.
• Websites - In this notebook I store content I find on the web: usually clipped with the Chrome extension. This is more than just a bookmark: it has the full text and corresponding images, made searchable by Evernote. Besides, I still have access to the content when the original page goes 404.
• Inbox - All stuff which is relevant to me at this moment: things I need to remember, drafts I'm writing or other items I have to deal with one way or another.
• Archive - All items which are not relevant anymore move from the stack's inbox to its corresponding archive.

This type of categorization is still a bit coarse-grained, so I use tags to make it easier to refine my searches. For example, I maintain tags for each course I follow at the university and a set of tags describing the 'type' of the note (lecture, documentation, video, minutes, ...). I also maintain a special tag ToRead to mark all items I need (or want) to read at some point. Whenever I have a dull moment, this tag always provides something interesting to read.

And finally, what do I store in Evernote?

• Bookmarks
• Articles
• Newspaper snippets, taken with my phone camera
• Lecture slides
• Books
• Some passwords (obviously after I encrypted them)
• Meeting minutes
• Business cards
• And more

Conclusion

Evernote is possibly the greatest way "to backup your brain". You can store almost anything inside and a piece of information is always easy to retrieve thanks to their presence on almost every platform and powerful search capabilities.
After two months of intensive usage (and having 544 notes at the time of writing) I have to conclude that it will be difficult to live without this service.

Update 1 April 2011
So not long after posting this text, Evernote published a new web interface. It has not all features implemented yet, but still it's a great improvement over the old one.