This is an apparently true article where the doctor who worked on a penis-reattachment explains that:

'The severed end of the penis was "stored" in the patient's forearm--temporarily sewn into the limb--so it would receive blood for the month it took for the wounded crotch area to heal and allow reattachment. Oh, and how did this unfortunate chap come to lose the end of his thing? "It involved a lawn mower," Jacobs said. "I really don't know exactly how it happened."'

See: http://www.citypaper.com/2001-12-12/nose.html

Another interesting quote from that article:

Next, he held up one of his "favorite items in the collection," a small metal ring used to protect the "moral fiber" and "life forces" of boys about a 100 years ago. Known as a spermatorrhea ring (and once sold through the Sears catalog), it controlled nocturnal emissions as well as the "secret vice" (er . . . whacking off). The ring fits loosely around a flaccid member, but, as Engel explained, "when erection occurs, 50 steel teeth bite into the penis, and the erection disappears." No doubt.