Coming this August to a Playstation peripheral vendor near you (assuming you're in Japan, that is): the 160 GB external hard disk drive for PS3 from Hori.
It'll cost you about $240 (yikes), but on the up side, it connects to your PS3 via the USB port, which it also uses as a power source. I don't know, though, is the extra room worth it?
PS3 Add-ons [IT Media, via Kotaku]
