Just got more bad news, chatting on IRC with a guy in japan who has a PSP. In the instruction manual for the system, it specifies that the PSP will ONLY read discs/games that are region 2 or region ALL only. Currently, the two games he has both have a region two logo on them. Presumably, US games would be region one. Here is his exact translation of the japanese from the manual "with this machine, UMDs displaying the region code ALL or 2 can be played".
SO apparently, the PSP's may be region locked after all
SO apparently, the PSP's may be region locked after all