torque wrenches
check out this thread from a while back:
http://forums.mtbr.com/showthread.php?t=170627
You really need two wrenches; one low range, 0 to 60 inch/pounds, calibrated in increments of 2.5 inch/lbs, that will work for most of the threaded fasteners on a bike so you can be sure that you aren't over-tightening bolts for calipers, bars, controls, etc, and especially if you are using carbon components.
A medium range would be 50 to 600 inch/pounds, calibrated in 25 inch/pounds will work for the larger fasteners like crank bolts.
Keep in mind we are talking about torque wrenches that measure in inch/pounds, not foot/pounds that you would find in an automotive toolbox.