I'd like my phone to automatically go into silent mode when I put it on the Touchstone.

When I'm at work and my Pre is on the Touchstone, I'm right there, so I don't need to bother my coworkers with a ringtone. Also I don't want it ringing when I leave it at my desk and walk away.

Yes, I can just turn the ringer off as I do now, but I keep forgetting to turn it back on at the end of the day, so an auto- solution would be great.