I know that I'm probably going to get a brain tumor, but I have to recommend the new headset I just picked up on Ebay:
http://www.freetop.net/htmls/microtooth.html
I also purchased the in-car docking station/hands free adapter:
http://www.freetop.net/htmls/Multitooth.html
Ebay vendor was Green Mountain Traders (whom I also recommend):
http://www.greenmountaintraders.com/
The headset is very light, and works flawlessly with my Siemens S55. The sound on the headset and the in car adapter is great.
All for $120...