i have had a suntour XC Pro front friction shifter for my rear derailleur (kick-shift for the front) for the last 4 years or so and i love it for trials (it sits on top of the bar and i don't whack my knee on it). now that i'm doing more trail riding, i'm going to actually get a front derailleur and use it to switch between my 32/20, and run a 17T SS rear wheel.

friction works pretty well, but if you want something that you won't have to fiddle with on the trail, friction is definitely NOT the way to go. i like it, but then, i'm somewhat of a retro grouch/masochist.

learn to adjust your derailleurs properly.