MicrostockGroup

I just saw this blog post from Scott Bourne:
http://photofocus.com/2010/04/08/the-ipad-offers-new-markets-for-photographers/

When I follow his link it seems like images are wrapped into app which allows user to save them on their devices. I do not have iPad to test it so I am trying to guess if images are downloaded from the web or packaged with the app.

Ha.  If only.

I'm a software developer and if I could, I'd write one today and start selling it.  the IPad and IPhone are "closed" systems, meaning you can't just write a program and install it.  The only path is to get your application accepted into Apple's online 'app store'.  That costs money, takes time and involves some very strict rules and limitations on your program.  Even if you create an app that follows all the rules, there's no guarantee that Apple will accept it, in which case you've wasted your time.

I believe Apple would also have to approve all wallpapers you'd want to offer through your application.

I believe you have to pay $100 a year just for the privilege of being in their store, assuming they accept your app.  

How many people do you see buying wallpapers for their computer? Pretty much none. I think pursing this would be a waste of time. Time that would be much better spent shooting more.

Not sure. Computers are for people who know how to edit and use their own pictures as a wallpaper. iPad and similar toys are for everyone: if there are people downloading (ugly) ringtones, why not selling them wallpapers?