We want a new Twitter background for our Twitter account, http://www.Twitter.com/RapDevPro. We LOVE the AngryBirds Twitter background and want to create a similar look using graphic assets from a variety of our apps. Another Twitter background we like is the one for PopCap (makers of Plants versus Zombies).
Since we have a lot of different apps with a lot of different art and styles, the challenge will be to make something that looks appealing across all of our apps. (A wide variety of art will be uploaded for the designers to leverage.) One simple approach would be to tile our various app icons, but the winning designer will do better than that.
For example, perhaps you could collect some of our like apps and characters into "Islands" where each island promotes one of our app-brands.
We are open to just about ANYTHING, as long as it represents our apps in a positive way.
And one additional thought -- the design should support adding new apps as we have several under development and are always releasing new apps. This is one reason why that "Island" concept mentioned above might be a good way to go.