I run Graffiti on Facebook (http://facebook.com/graffitiwall). It's a top 50 Facebook app (with a higher user rating than any in the top 100+) that lets users draw for each other using a very simple interface. We have so far neglected to build Graffiti for the iPhone or the iPad and I think that's clearly a mistake since it seems like a perfect fit. Obviously it's a short time frame, but we'd really like to finish it before the iPad launches in a month or so, if possible.
The application will be simple: the user will draw (using color, width, and opacity), and then be able to send to a friend via facebook or email. There will also be a way to view Graffiti the user has sent/received, and ideally a way to replay the drawing like we have on Facebook Graffiti. We can handle most of the design but don't have any experience making iphone apps. It will most likely be a free application and we're going to promote it heavily from Facebook Graffiti.
Should be a fun project. If you're interested, shoot me an email at hn.jobs.tmt [at] gmail.com with your resume and links to any iphone apps you've built, plus your rates.
This is a great idea, and I hope one way or another you guys get the app done. Facebook applications are ready to break out of the walled garden, and this is the first step.