I think you have the looks to try a Lady Godiva costume:
http://www.amazon.com/Godiva-Adult-H.../dp/B000LTOY5M (easy to find at a local costume store)
Sure it's really just a long wig but to wear it properly, you're completely naked otherwise! I'm sure the wig could be "affixed" in certain ways to keep your nipples, pussy and asshole concealed!
If you feel too "bare" underneath, add this to the outfit:
http://www.amazon.com/Fishnet-Body-Stocking-Available-Colors/dp/B000OIKU8U/ref=pd_rhf_dp_shvl3 (easy to find at any lingerie shop)
For an added bondage aspect, handcuff your hands behind your back and ask anyone interested to help you find the "hidden" key somewhere on your body!
The "hidden" handcuff key idea provides other people the opportunity to physically "search" your costume to release the handcuffs. Of course, if the key is actually in another location, the intensity of their "search" efforts could be very "stimulating"!
BTW: I've revived my "Halloween Dares" thread on gD for 2011:
http://www.getdare.com/bbs/showthread.php?t=60096
Check over there for any new postings!