Go for it. It won't save much weight, but if it's easy enough in the Geo, then I say go for it.
Does your AC run on a separate belt, or does it run with power steering, or an alternator? If it's separate, you can just get rid of the belt and forget about it, otherwise you'll have to find the accessory belt for the non-AC version of your car.
The compressor will be the heaviest thing, but only about 15lbs or so. The lines weigh virtually nothing, and the condenser and evaporator are pretty light as well. It will make the engine bay look cleaner though, without the AC lines going through it. I suppose it helps with cooling the radiator as well, since it won't have the condenser in front of it.
Overall, I think I figured it was about 25-30lbs saved. So it's really not much, but you're also eliminating one of the belts from the engine, so that can only help.
Before you do it, get the AC discharged at a shop, to remove the freon inside the lines.
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