I have tried wrapping a tattoo with saran wrap for 48 hours (cleaning and rewrapping it a couple times a day of course). The guys that told me this method of healing recommend it for color tattoos, but not for black and grey work. Apparently, since black and grey work isn't as traumatic as full-on color, so it isn't worth all the grossness that accompanies keeping your tattoo wrapped up that way.
One of the best benefits?! I was in Hong Kong at the time, and in a city full of germophobes, nobody wanted to bump into my arm because of the crazy looking bandage I had on!
The color came out bright as hell, and the healing after I stopped wrapping it was way more comfortable than the usual moisturizing technique. The skin that peeled off I felt was thicker than normal, but none-the-less a very effective way to heal a tattoo.