Do you want to plug Xbox 360 (or any other device with an HDMI output) into your glorious 27” iMac screen? Well good news folks, you can do just that with the new Kanex HDMI to Mini Displayport adapter! It’s sexy (as a box goes), with a brushed aluminum shell to fit in with your awesome looking iMac.
The bad news is the price, which is approximately £125.99/$108.45 (yes yes, our “friends” over the pond get it cheaper). This sounds a lot (which it is!), but it is an active converter (the Displayport doesn’t accept a HDMI or VGA signal so it has to do a whole load of fancy jiggerypokery), so your normal external monitor cable can’t do the job.
One useful feature (if you live with the tedium of not owning a 5.1 system), is that the converter also sends 2 channels of Audio. I find this useful because I use the same speakers for my iMac as my Xbox 360 and this functionality works seamlessly. Of course you could use this to plug in a variety of devices like a Blueray player or HD Freeveiw box which means there is now no reason at all for a TV.
However the main draw back of this setup is that the Displayport will only accept a 720p input!! Crazy, however Kanex say that if Apple ever become the caring people they claim to be and enable the graphics card to receive 1080p their device is ready for it.
To round up this is a great product for a problem which should never have existed. It’s an expensive option, but if you have no other display (or at least not one as good as the iMac’s) for your HDMI device in my opinion this is your best and cheapest option.

Can’t believe I didn’t know you could do this. I remember wanting to do similar with my laptop years ago, a serious plus for the Mac crowd in my opinion.