B737-700
Conflict NMAC
Flight Crew Took Evasive Action
Environment - Non Weather Related
Approaching 10;000 FT MSL; saw three powered gliders in flight path. Captain disengaged autopilot and started left turn with an additional climb to miss gliders.  Passed 300 FT from one glider and within 800 FT of all three gliders.  Advised ATC of the gliders' location.  Continued to RNO uneventfully.
B737-700 First Officer reported NMAC with three powered gliders on approach to RNO.