27-inch iMac, we have good news for you. Belkin has introduced its AV360 Mini DisplayPort Converter, which takes an HDMI input at up to 1080p and squeezes it into a Mini DisplayPort connector at 720p for display on your iMac. It'll also push stereo audio through and is HDCP-compliant, so even protected content from your Blu-ray player will get by. The cost? $150, which is cheaper than getting a second display, but an awful lot for a converter box with a single input
Update: We got it wrong on the MonoPrice reference here. That adapter goes the other way!