If you have a Mac that was introduced from mid-2010 on and it has a Mini DisplayPort, Kanex has a couple of solutions that can turn your HDTV or other HDMI-equipped video device into a monitor with full audio pass-through.
I recently had a chance to test out two such solutions from Kanex. The first is the US$29.95 Kanex iAdapt V2, which is an adapter that plugs into the Mini DisplayPort and has an HDMI port on the other end. It's useful if you already have an HDMI cable and just want to be able to plug it into your compatible Mac. The second is the $44.95 Kanex Mini DisplayPort to HDMI cable, which combines the adapter with a 10-foot long HDMI cable. You plug one
