1. Find Some Themes
2. Download Themes
3. Put a Usb Key in Your PC
4. Transfer the Theme in A Folder Called: PS3/THEME/*Put Your Theme Here*
5. Put the USB Key in Your PS3
6. Go to Settings - Theme Settings - Theme and click Install.
7. Enjoy Your New PS3 Themes!
This is just what I was looking for! It might be old information for some but not for us noobs. I was a little confused at first until I finally woke up and realized that the "PS3" folder had a sub folder named "THEME"... :duh.