Here's what I carry. The adaptor is usually banded up with earphones, pulled out so you can see how little extra 'crap' it actually is:
BudsAdaptor.jpg
It's been almost a year since I got that adaptor, along with 6 or 8 others that I use for other set-ups (car, office, living room, ActiveSync, travel,...). But, here's something close if not the very same item:
http://tinyurl.com/5mxnr4