I want a drum machine, but don't know what to buy....

I got a "USB roll up drum machine"... it's pretty cack.... it just isn't responsive enough, when drumming at any speed it just dosn't catch all the hits I do!

What I think is that turning my computer (Mac in this case) into a drum machine would be cool.... so if some adb keyboard/joystick no, an adb drum pad? I could allways hack the usb drum pad & then wire it up to adb?

I would need somebody to write the software, anyone interested? at all?