I like the idea of Dropbox Apps. A user can consume your web service without even leaving Dropbox (almost). To demonstrate the concept I built <a href="http://BoxySign.com" rel="nofollow">http://BoxySign.com</a>.<p>- Drop an unsigned document in your Dropbox BoxySign folder, and you receive a link.<p>- Share that link to receive a signature.<p>- The signed copy is then delivered directly to your Dropbox BoxySign folder on your computer.<p>You can do all this directly from your Dropbox folder, but there is also a web interface which the video demonstrates - <a href="http://boxysign.com/video" rel="nofollow">http://boxysign.com/video</a><p>Additionally (depending on how you architect it), it saves big on storage costs. You can store pieces of data in hidden files on the user's Dropbox.<p>I think this has neat potential for many types of little Dropbox Apps. Thoughts?