If I'm going to wireless tehter to my Android phone what method drains the battery the least? Wifi or Bluetooth?
I decided to look up some data, and my guess seems to be correct: http://nesl.ee.ucla.edu/fw/documents/reports/2007/PowerAnalysis.pdf
According to the report, Bluetooth takes the least amount of energy.
However your 3G radio will probably take the most energy; maintaining a 3G connection without transferring any data is cheap, but once you start sending/receiving data, then it trumps even Wi-fi.
Disclaimer: The study might only apply for the particular model that the device they use.