I want to take the belt off the ac pump thing in the winter, so it would be less strain on the engine which would equal more mpg. Would it actually help? I would of course need a shorter belt.

Maybe a little, but remember the compressor only runs when called for by ac or defrost, otherwise it just freewheels. You would also lose your ability to defrost...

Wouldnt make a difference, as said above, A/C compressor only runs when its turned on anyways, so during winter your not using it so its not causing drag.

You need to keep the belt on. It engages during defrost to remove water vaper from the air. It also saves your compressor, otherwise the oil in the ac system will settle and cause dry run whenever you decide to use it again.

Am I missing something here? There is only one belt...the serpentine belt. If you remove this, you loose power to all accesories (power steering, alternator, water pump, etc).

When at idle, the ECU will engage the AC compressor for short bursts to cycle the R-134a in the system. However, I don't know if the ECU continues to do this under driving conditions, when the AC is not selected. Either way, even if you did have a seperate AC belt, deleting it in the winter months would not net you metter gas mileage.