Putting the phone online: dialing my ISP's connection on the phone, my reception stays the same. Battery usage stays the same.

Putting my laptop online: using the bluetooth DUN profile to dial the connection and having everything sent via bluetooth, the battery drains horribly.

The way I understand it, lower reception causes higher power consumption because there's more power put to the antenna to get a better signal. So normally, I'd have 3 bars with the normal amount of power for the antenna. However, with BT tethering, the antenna uses even more power to get me from 3 bars to 5 bars and from 3G to 3.5G.

About the orientation: The phone is at the very same position it is when not used to go online with my laptop.