Yes, 1TB 2.5" HDD exists, WD's Scorpio Blue or Toshiba's MKxx59GSM

but I really doubt you can't use it on the PS3. Why? Cuz if you look at the specifications, the physical dimensions of the drive is 12.5mm , where as, having gone through a lot of threads on PS3 HDD upgrading, the HDD must be a 9.5mm

Correct me if I am wrong on this though