Probably best known as a gag item from the Austin Power movies, penis pumps are one of the few proven methods for increasing the size of your penis. Penis pumps work by creating a vacuum that pulls and tugs at the tissue in your penis. This causes the tissue to gradually increase in size and mass. While penis enlargement pumps do boost your girth and slightly enhance your length, these are mostly short term gains. It takes months of dedicated and prolonged use of penis enlargement pumps to permanently boost the size of your penis. Of course, penis pumps also serve other needs. Some doctors even prescribe penis vacuum pumps for patients that have difficulty achieving or maintaining an erection in the first place. There are some penis vacuum pumps that come with a built-in vibrator so they can double as a masturbation device. And never discount penis pumps when it comes to finding a gag gift for a bachelor party.