I just upgraded to the latest version of Evernote for Android. I'm not sure what went wrong, but after the upgrade, every time I tried to create a snapshot note within the app, I received the error message “No snapshot found to upload” right after taking the picture. The solution: Make sure all pending notes have been sent and then delete the "Evernote" folder on the phones memory card.
Don't worry, all of your data is in the cloud, and whatever was in that folder will be re-created as soon as you start Evernote again.
Update 2010-07-27: Nope. This didn't help. The problem came back. Apparently, if you wait a really long time between taking the picture and pressing "OK" will help. Apparently, there is a "race condition" where Evernote expects a snapshot to exist as a file somewhere yet the file is still being written to storage. Apparently, there is a new beta floating about that fixes the problem. You can get it by surfing to: http://s.evernote.com/androidbeta.