As every electric motor is also a generator, yes. Just put something between the blades before you blow it out.
Those cans suck ass, at least for my experience. As the content cools of through expansion, you have about 20secs of charge before you have to wait for the can to get warm again :-/ but results may vary
Thats something i didnt try, thanks for the input. But since i got myself a proper air compressor, i dont use these cans anymore