Contrary to what continuum says (he's usually spot on, though), it's quite normal for a HDMI to VGA adapter to be fairly warm. Ballpark figure for a HDMI to VGA decoder is around 200 mA at 5 volts.

Atlona Technologies have announced the HDAiR, a wireless USB to HDMI or VGA adapter which allows cable-free connectivity to a display from up to 30 feet away. Using UWB, up to 720p or 1440 x 1200 ...