I can't find the answer to this anywhere, which doesn't bode well. Can you have a single account on multiple PS3s? I know one account can cover a PSP and a PS3 so it seems possible, but I need confirmation. I have also found the inverse, many accounts on one PS3, but that doesn't help.
Here's my issue, my nephews have a PS3. You can download games to a certain number of machines (can't recall the number). If I could be on their machine also when I'm at their house I could put my downloaded games on their machine and play them.