best app ever. not only can you silence your phone at pre-set times, you can turn wifi, bluetooth on/off at preset times and save precious battery juice. this is a must have app!
I use it to silence my phone for classes. And obviously, it turns my ringer back on when class time is over.
You can also give Tasker a shot. It's a bit expensive but extremely powerful. UncleMike who's on the Bionic forums a bit is a master of it. Try it out. Steep learning curve, but tons you can do with it.
