to grab a fridge compressor from all these fridge lying around in the streets due to bulk waste.
( just need to cut the compressor from the rest of the fridge with a cuttingplyer)

You could use it to do a vacum pump (or a little compressor). Vacum pump are really cool to have when you need to make a sandwich board, cimply fix your board, fix delamination by sucking the skin back on the foam, take water out...etc.. a good thing to have lying around in your garage.