If there was a button in the iPhone app that you push to “Attach from Dropbox” that would open up your dropbox account and allow you attach a file, that would be the way I would like to see it. If you don’t really like Evernote (like me) you don’t have any way to attach files to projects unless you are on a desktop. I am a GTD guy who has gone 90% paperless. My “inbox” is in Dropbox. When I process the scanned documents that are in my inbox, I frequently establish a project for an item in my inbox and attach the item to the project in Nozbe. If I am processing my “inbox” on my iPhone, I have to wait until I am back at my computer to do this. It kind of gets in the way. I still don’t understand why so many people like Evernote. The UI is gross.

@Dave – here’s another thead about it: just FYI http://www.nozbe.com/gtd/forum/section-1/post-9d289f1/link_to_dropbox ;-)