PS3 games are typically developed with a devkit that costs about $10,000 in C++ using propriatory Playstation APIs, where you optimize your game for its multicore processor. An experienced gamedev once commented that the PS3 is far harder to write for since its multicore pipeline is unusual and requires special efforts to optimize game code.
Another method would be installing a Linux OS on your PS3 and then developing your program for that breed of Unix, either in C++ or any other supported platform. This is quite cheap since you can manage this on any ordinary PS3. (no expensive dev kit needed)
Developing for the Xbox 360 on the other hand is free for students, I recommend you start with XNA for Xbox 360 since there are many open source games and game engines to help you out.