I have no idea about HDMI cables, but for RCA and component cables, you should just be able to buy a Y-splitter for each cable. You can get them at electronic stores. And you will need a cable to run from the splitter to your other TV. You will also need a male-to-female converter for each splitter. Just plug the PS3 cables in to the splitters, plug the splitters into your TV, then plug a male-to-female converter into the free splitter cable, then run a cable to the other TV.
Or, if your TV has line out jacks, just run an RCA cable between the TVs.
option 1 HDMI just make sure that the hdmi cables you get support audio.
option 2 RCA
when you buy a ps3 it will already come with an rca cable.
if youre using rca cables i would suggest getting ones with gold connectors.
if youre using hdmi cables make sure to get ones with audio capable AND that its long enough.