Both k100d and k10d
Especially with pentax. I photograph a lot of streams in the mountains and constantly find myself switching between my lenses. I have resorted to two cameras, one on a tripod and one not. I usually hand hold a wide angle and mount mount a more telephoto.
If, pentax had a 24-120 equivalent like some of the other guys, I wouldn't have to do this so much, but as it, they are the king of lens splitting!