Simple JVC GZ-HD7 headphone solution
 

Goto radioshack and buy part #274-368 called a Stereo-to-Mono audio adapter. Accepts 1/8" stereo phone plug. Fits 1/8" mono phone jack.
The above is what is on the package so you can identify it. It cost like $2.
Plug it into the AV port and plug your headphones into the adapter.

Simpler than any of the solutions I've seen posted on the net.

Basically how it works is, you know if you just plug your headphones in you get one ear of static and the other correct sound. The mono plugs just pulls out the one side of audio and ignore the static side. You will be getting mono sound instead of stereo, but for monitoring purposes I don't need stereo.

HA!
Brilliant, Thanks Eric. I had one lying about and it's all I need too. Excellent.