It depends what you mean by "advertise."
Are you a manufacturer or an agency working to prevent unwanted pregnancy and/or sexually transmitted diseases?
Or are you a player who wants potential bed partners to know he's got coverage?
If you're the former, humor and good taste come to mind. I realize the two are not exactly synonymous, but I think working up an ad campaign which exhibits both is doable. (If you've never seen it, rent The Closet - the French film that came out in 2001.)
If you're the latter, I don't suggest you make any such advertisement unless and until it becomes evident that the lady (or gentleman) in whom you're interested has the same thing in mind.
And in that case, I don't think it'll be necessary to 'advertise' much of anything. Your body will do all the advertising for you - just be sure to glove the love before you start!
