The TechZone has posted a review of the XtremeMac HDMI Switcher

So, you've got an HDTV with just one or two HDMI ports, but you've got that high definition satellite set-top box, you've got that glossy wonder
known as Apple TV, you bought yourself an HD DVD player in preparation for
your new home theater experience, and you're itching to get in on some Virtua Fighter 5 or Resistance: Fall of Man. But you don't want to have to
crawl behind your TV each time you want to switch sources. Well, that's where
this lovingly simple solution comes into play. The XtremeHD HDMI Switcher
from XtremeMac is simplicity itself. It swallows up to four HDMI sources and spits out a single HDMI cable that you can connect to your HDTV. There's no
strange configuration to consider, no software to setup. Just plug it in and it's good to go.

XtremeMac HDMI Switcher Review