Over time more and more wallpaper will be added to this thread. To start, here's our official GeekDrop Thunderbolt wallpaper! To download it and add it to your phone just right-click in the wallpaper and choose "Save as .." or "Save image as .." (whichever your browser decided to name that ), and add it to your device.
This particular wallpaper is designed for the HTC Thunderbolt screen resolution, so it may or may not perfectly fit your own device. You may need to crop / stretch / etc. it to fit yours. Other resolutions will be added soon (fir example the DroidX resolutions, and so on). There's also a nice, free Android app named Wallpaper Wizardrii that works excellent for making any wallpaper fit your device.
If you have any requests, tweaks, etc. just post and let us know! More to come!