  While of order a million asteroids have been discovered, the number in
rigorously controlled samples that have precise orbits and rotation periods, as
well as well-measured colors, is relatively small. In particular, less than a
dozen main-belt asteroids with estimated diameters D<3 km, have excellent
rotation periods. We show how existing and soon-to-be-acquired microlensing
data can yield a large asteroid sample with precise orbits and rotation
periods, which will include roughly 6% of all asteroids with maximum brightness
I<18.1 and lying within 10 deg of the ecliptic. This sample will be dominated
by small and very small asteroids, down to D~1 km. We also show how asteroid
astrometry could turn current narrow-angle OGLE proper motions of bulge stars
into wide-angle proper motions. This would enable one to measure the
proper-motion gradient across the Galactic bar.
