I am in the market for a new cell phone. Decided on the Treo series I think. I like the idea of a bluetooth headset, but not sure of how you answer calls with them. I know some wired head sets allow for answering. My concern is that this will be the only phone (deciding on going landless) - that BT might take more power than the 600 option. Plus I am looking at $100 to $150 extra for the 650, and other than BT - can't see why one over the other. Thanks for the help.