Well, for the most part the requests are
all up to you. The only major rule I have is that they pertain
to anime/manga. I know about the Plastik T-shirt series, which
really isn't anime, but the style is so if you find anything
like that I'd be happy to make a wallpaper for it.
If you find a picture that'd you'd like to see on a wallpaper
just email me the pictures address or the picture it-self.
Otherwise, if you just have a series you'd like me to make
wallpapers for, it will depend on if I can find decent sized
and quality images for it. But I can find just about any anime
series pictures, so just email what-ever you'd like to see