There is at least one Model designed for the outdoors by Silva which has a built in compass. If memory serves me correctly one can deselect the GPS functions and just use the compass option. It is electronic, and will show the direction in which the top of the unit is pointing without the unit requiring any movement.
I believe they incorporate a fluxgate magnetometer for the static bearing derivation. There are several (handheld) models that have this functionality including Garmin's eTrex Summit and Vista models - which also have barometric altimeters. A sensible combination - adding the GPS to the compass means that local variations in magnetic declination can be automatically compensated for.
Ok... Enough waffling on subjects on which I know not nearly enough...
m.