Here you can create your own USplash theme without the knowledge of C or compiling.
Just upload your graphics and configure, and you will get a custom .so file for your custom theme.
The script will currently only generate 1024x768 themes.
As this is a beta release, parameters for setting the text-color parameter and the like is missing. These will come later.
Hints: You will need 3 images in 256 color png format. A background (1024x768), a progress-bar, and the background behind the progressbar. The size of the progress-bar is customizeable. Important: All images must have the exact same palette.
Update: The generator had some problems generating the .so files after a recent server move. But it should work again now.