Saw this somewhere else and thought I'd pass it along, Monster is giving away in-ear tips in exchange for a review on them. I got these tips with my turbine pro coppers a few months ago, and they definitely beat any stock tips I've used with headphones, past and present. My brother is also using them on his sennheiser in-ears. They have a big list of compatible headphones on the site:
http://monstersupertips.com/contest/default.asp
http://monstersupertips.com/contest/default.asp