iPhone Mockup looks like a cool proof of concept for a sketchy mockup app for iPhone. It's a bit like Balsamiq in spirit, but is done completely with JQuery. Firefox and Safari are the target browsers, and there is no option for doing secure mockups. Whatever you do will be visible to the world, so don't plan on using it for anything other than playing. Nice concept though.

Thanks, Andrew.

http://iphonemockup.lkmc.ch/