This is also how you can access the different Sony Stores outside your region. Create new users, and make their location in the same region as that Sony Store. Just one thing to remember, the files/games will often be in the language of that region.
One question though for those in the know, how many different users are you limited to on one PS3, and is there, or will there be away to play under your user name on someone else's PS3?
For instance, if you are going over to a friends house to play with them on their PS3 and you want to play under your user name for reasons like stats, friends list, etc - is there a way, or will there be a way to do that? Perhaps this might be possible using a USB drive, transferring your user information temporarily over to their PS3?