There are plenty of wallpapers for your psp that you can find online. Just use google. Be specific when looking for psp wallpapers. For instance you want anime psp wallpapers or sexy psp wallpapers, so use that keywords.Don't just type in psp wallpapers or psp themes. Be as specific as possible and expect to get specific results.

I will update this post for specific links where you can download psp wallpapers. For the mean time you can visit - PSP Hub for PSP wallpapers.