I am a massive fan of evernote, it's one of those applications that I can't do without. I type all my notes into it, scan everything into the application, I basically have it open all of the time.
I like to ensure that every note is filed into the relvant notebooks and more importantly that every note is tagged. Occasionly I will file a note a way without tagging it, and then trying to find them again is a pain. However there is a very simple way. Click on "All Notes" then in your search box if you type
-tag:*
This will show all notes that don't currently have a tag associated with them.
I am always interested in feedback so please feel free to add any comments, or you can mail me here. If you would like to submit a quick tip with full credit and links back to your site then also feel free to contact me.