I don't recommend duct tape for taping off areas that you don't want paint to get on - the adhesive is too strong.
I've also read that you CAN make a pretty good substitute for those self stick bra cups to wear under clothes that bras don't work under - but taking it off is murder on your skin - at best it leaves the area rather raw and at worst it could scar. So it sounds like one of those ideas where someone tried this already and really didn't like the way things turned out.....
since this is the thread for dire warnings...
double sided (clear!!) tape is splendid for certain dress up occasions. It can hold a pesky strapless gown in place, work in place of a strapless bra, and mend tears. all at once.
If you normally use nice clear toupee tape type substances and, the night of a formal dance, your seam rips and you're stuck, do NOT take up your roomie's BFF's suggestion of clear carpet tape.
I was the girl w/ the carpet tape and I should have thought it through better because at 2 am, trying to get the stuff off the girl's skin w/o killing her or dousing her w/ chemicals was most unpleasant. But, in a "CRUD MONKEYS!, we're idiots' sort of way, dang funny. :-)