Add a headphone jack to monitor audio when shooting in movie mode

Hi;

One lack on all EOS rebel series cameras is the lack of a headphone jack for monitoring movie mode audio.

I'm wondering if this adapter will work;

http://www.amazon.com/eForCity-Compatible-MINI-USB-HEADPHONE-ADAPTER/dp/B003DS8LFC/ref=pd_sim_e_5

It says it is compatable with an HTC G1. But I'm guessing it is just an mini-USB to audio just as the cable supplied with the M is.

Any thoughts on this adapter as a headphone monitor?