I'm so pale I'm practically see through. So I've incurred my share of bruises, too. I usually try to wear clothes that cover them. If you're talking about hiding them while at the club or on a date, you can try a sheer black blouse/nightie. By the time you're removing it, no one's really gonna' care.
Once they fade to that lovely yellowing stage, it's easier to get by with make up.
=)