I picked up a device called a DSLRCable for my 7d (can't post links yet) and it works really well except the fact that I don't have a good workflow for it yet. What it does is it plays a dummy tone on the left channel while recording. This fools the camera into thinking the environment is louder than it is and turns off the automatic gain control which normally causes an unwanted hiss during playback. In post you delete the tone and duplicate the good audio track and put that in its place.
I use Premiere Pro CS5.5 and found that dropping the Fill Right effect over the audio track does all of this automatically. Unfortunately I cannot find a way to control the Source audio track so when trying to make clips out of the raw footage I get the tone playing over the good audio and cannot make I/O points with the dummy tone playing over the footage.
Its not the end of the world if I can't use the Fill Right effect trick but I would like to find out the fastest/simplest way to get my audio up and running.