You also might want to check out libwebcam and its command-line
configuration utility, uvcdynctrl:

http://www.quickcamteam.net/software/libwebcam

$ uvcdynctrl -d /dev/video0 -g 'White Balance Temperature, Auto'
1
$ uvcdynctrl -d /dev/video0 -s 'White Balance Temperature, Auto' 0
$ uvcdynctrl -d /dev/video0 -c
Listing available controls for device /dev/video0:
[...]
  Focus (absolute)
  Exposure, Auto Priority
  Exposure (Absolute)
  Exposure, Auto
  Backlight Compensation
  Sharpness
  White Balance Temperature
  Power Line Frequency
  Gain
  White Balance Temperature, Auto
  Saturation
  Contrast
  Brightness

 - Ken