Hi Rich,
I just did one by one, put a memory stick in the PS3 and used PS3 to connect to internet and save link as for each map, after each map downloaded, I would go back into UT3 and install map. Then just repeat and overwrite jam file.
Not sure its any faster than downloading and renaming...but like hone said there aren't that many maps. Also for the new folks don't forget the free downloadable content (maps) in PSN store.