It appears Sony's intent to at last embrace the MP3 digital music format (alongside their own proprietary ATRAC3 format, of course) will not just be limited to their dedicated portable music players, as GameSpot learns that MP3 support could be coming to the PlayStation Portable (PSP) as well.  There is also talk of giving users the option to download videos from PC into the PSP as well:

"According to [Sony Computer Entertainment network systems chief Izumi Kawanishi], PSP owners will be able to download MP3 files by connecting the handheld to a PC via the USB port. The PSP will then be recognized by the PC as a USB mass storage device, and PSP users will be able to simply drag and drop the MP3 files from the computer's hard drive to the PSP.

Kawanishi also mentioned that the PSP will be able to play back video files, in H.264/AVC MP Level3 format. SCE is currently debating whether to release a tool for the PC that allows users to convert videos on their computer to the supported file format, said Kawanishi. In any case, since the PSP has no video out jack, users will not be able to play back movies onto an external screen."

The article confirms that MP3s downloaded onto the PSP in this manner will need to be stored on Sony's Memory Stick Duo media cards, and not on their new Universal Media Disc (UMD) format like all PSP games and movies.  This makes sense since Sony itself admitted previously that they would not release any blank UMD media and compatible burners to the general public.