actuating a brake or anti-backdrive

[loafdog]

Hi,

We don't plan on using pneumatics on our robot so I was looking for ideas that used something else to control/move a mechanism that would brake/stop elevator.
I was wondering if servos can be used to control brakes or some other kind of anti-backdrive component. Poking around andymark I saw shifting gearboxes controlled by servos for example. I've seen people on CD discuss bike brakes, ratchets, etc..
But I haven't seen anyone discuss how you can implement these ideas. Anyone done this before and have details/pics they can share?

(note, I'm not a mechanical type.. i do software, just trying to get ideas to share with my team).

THanks.
-Maciej