Thanks, everyone for the tip on using Jabra Eargels with the HBH-660. For those who want to get Eargels, this is the best deal I could find:
http://store.yahoo.com/exchangecellular/jaea2wi6ea.html
For $4.94 shipped, you will get a set of 6 Eargels as well as a Jabra Earbud headset (to give to someone without the fortune of a Bluetooth phone).