Can I input a video signal into my HTC phone to use it as an external monitor of a camera? I'd like to use my HTC Evo 3D as an external monitor for my Canon 7D camera. The Canon 7D has a HDMI output. It also has an USB port, naturally.

I was wondering whether this would be possible. I think the USB/MHL port on HTC Evo 3D is for output only and it cannot receive any signal inputs. Is that right?

That would leave the USB port for this. But I still don't know how to achieve it.

I want to achieve something like this:
If your HTC phone has OTG support. You can use one of these USB OTG adapters. Then you can plug your 70D using a mini USB cable and then plug it in to the OTG cable and plug it into your phone. Then you can download an app such as DSLR Controller and you should see  live feed of your 70D on the phone.