It's pretty simple. Once you fire up the game and enter the online passcode in the instruction book, you can access something called "Community Creations". In that are all the arenas, CAWs, etc. that people have uploaded. If you press the Square button a dialogue box pops up where you can enter search parameters. If you search for CTW you'll find all of my creations, plus one or two that other people have uplopaded using the same tag. You can select my CAWs from a list and view them and download them to your PS3, and play as them.
Just a note for everyone reading... this is why I do directly to Doc with my questions.
I was wondering what that online thingie was for! Thanks, man.