Here are free Summerboard themes that you can download for your iPhone. I hope that you will enjoy installing and using these Summerboard themes. They are carefully handpicked by me from various websites.
Moonlight Summerboard Theme - download here
Time Machine Summerboard Theme - download here
Realize Mod Summerboard Theme - download here
Sticker Summerboard Theme - download here
Somatic Summerboard Theme - download here
Doodles Summerboard Theme - download here
If you don't know what Summerboard is, then I suggest that you first read my article: iPhone Summerboard Source Code, Web Installer and Video Tutorial