I like it. It's neat and fun to play with, but I'm not exactly sure what to do with it. I think a little "What you can use Snapito for" or "10 ways to use Snapito" link somewhere would be helpful. I can imagine it being useful for web designers who want to show designs to people, but how else do you envision people using it?
Also (this is just a minor nitpick), it'd be nice to not have to enter in http://. I'm using Chrome.