EverNote - A single place for ALL your notes!
Fantastic note-taking application where one can use to store typed AND handwritten notes, memos, webpages, emails, documents, sketches, etc, etc. Equipped with multiple methods of finding notes: Search function, by time, categories, tags (they call it labels), keywords. Check out http://www.evernote.com/en/products/evernote/screenshots.php for screen shots of all different types of medium that were captured and stored as notes. Very handy to have around for people like me that requires lots of organization in my job, capturing not just computer files but also diagrams and other things that I tend to scribble on the fly. Can sync with many handhels and tablet PCs too!