Compensating for gyro sensor drift

All,

I am designing a control system for a hovering quadrotor. The MEMS
gyroscope (angular rate) sensors have a slowly drifting zero-rate
point. To me, the bias seems fairly constant for several seconds, then
jumps to a new value, and this pattern repeats. Both the time and the
magnitude of the jump seem random. I know the "best" way to compensate
for this would be to use a sensor fusion algorithm with another sensor
type, but I was wondering if there were a signal processing technique
that could be used.

I have tried using a low-pass filter and a simple "deadzone", and both
worked somewhat, but not as well as I'd like. I'm going to use the
signal directly for rate feedback and integrate it to come up with
attitude feedback, if that helps.

Any ideas?

Thanks in advance
Roy