Add buttons to your dslr?

[bighatphotography]

Is there a way to add extra buttons to your camera, like a battery grip accessory? Specifically canon. I own both a t3i, and a t2i that I occasionally use specifically for filmmaking. And it would be awesome to be able to add extra buttons to map functions I do alot, to.

 

[Dave442]

I've seen a control from Aputure that gives extra control on some Canon bodies. Probably doesn't let you map buttons.