Since you mention that your car is a manual, you might have a clutch that is shot. If it's a manual clutch (not hydraulic) it may be adjustable, but if it's so far out of adjustment that your car won't move, chances are pretty good it needs something more than just an adjustment. Were there signs of clutch slippage leading up to this issue?
Another area to check would be for a broken CV joint or half shaft axle. With the front differential in the transaxle, if one of the joints or shafts breaks, the differential will keep the car from moving much, if any.
-Rod