Graphics/Drawing tablet and PS3.
Yeah... you can connect a tablet to your PS3, and it will work just like a mouse. :p Actually, it's kind of better than a mouse in so many ways. Some tablets with programmable buttons will have different uses for different buttons as well. Amazing! Now to wait until a game supports mouse and keyboard on the PS3... :p
P.S.: Yes, your tablets will work with Linux on the PS3 by default as well. I've tried three different brands, and they all work. The only thing that's lacking is pressure sensitivity... but if your tablet is a cheap one, don't bother with the pressure sensitivity.