One of Evernote's neatest features, at least as far as I'm concerned, is its optical character recognition functionality, which automatically makes the text within an image file searchable. This multiplies the usefulness of the application by several factors -- for example, I can scan in business cards (or, if a scanner isn't handy, just photograph them), and know that I will be able to search on the company name or any other info on the card (including notes I may have jotted down) to find the contact information.

And Evernote's OCR does a pretty good job -- I've found its interpretation of printed material close to perfect. When it tackles my messy handwritten notes, the fact that it ever finds anything is a constant surprise to me. (Evernote will also search within PDFs if you have a premium account.)

Evernote also has a tool (that sits in the bottom-right notification area in Windows or the top-right menu bar in OS X) that lets you "clip" images from your desktop and drop them into an Evernote notebook. I've found this very useful when, for example, attending online meetings when a PowerPoint presentation was being given. Want to save some of the information in a slide? It takes only a couple of seconds to clip the info and send it to Evernote.