I use Evernote a lot. Coz you think of anything and you can use Evernote for that.
First it was for saving the usernames and passwords of the khazillion of sites I’ve registered in. Another note was made to save the important bank account numbers, registration numbers and the like. Yet another note holds the serial keys of stuff I’ve purchased.
Then I got used to saving quotes and other important notes in Evernote. This is made easy by the Web Clipper extensions available in Chrome and Firefox. You can grab any part of the page, even with pictures, and instantly save in a note in Evernote.
Since recently I started saving various measurements I take in notes. For example it hold notes for my shoe size, shirt size and so forth. Saved me from a lot of hassle. You can also take notes about what you loan to others, etc. If you own an iPhone or an Android life becomes much more easy coz you can capture images and instantly send them to Evernote. And tagging the notes can keep everything organized.
P.S. And here’s 100 random things you can do with Evernote: http://www.andrewcmaxwell.com/2009/11/100-different-evernote-uses/