There are at least 2 more boot screen options that I know of, other than flashing to stock.
http://forum.ppcgeeks.com/showthread.php?t=36062
Scroll down until you see "Upgrade your splash:"
There's a really cool boot screen made by CMONEX and also a very nice minimalistic one by Tobeychris.
Personally, I kind of like the "test" screen!