Got tired of the muffled sound with the GoPro, and decided to go with a remote mic setup that m4a1mustang came up with. Nothing fancy.
Hardware:
GoPro Hero 3 Black
Audio-Technica PRO24-CM Microphone
16' male-to-female audio cable
Fat Gecko "Mini" camera mount (with suction cup)
GoPro's USB-to-Female audio cable
Here's my one (and only, so far) test video I quickly made today, in the miserable cold and wet weather.