To all you GoPro Hero nerds.....

[JoniJo]

Has anyone tried to use the external mic jack? If so, Where did you get your cable? From GoPro?
I'm also assuming that you have to use the "ported" or "skeleton" back door as they call it to the case to allow the cable outside access.
Advice requested.........     

I'll bring a bunch of jerky.                          Thanks, Joni

P.S. See 'ya Thursday!!!!!!!!!     

[Bogus Jim]

It's just a standard 3.5mm stereo plug. You can buy a cable anywhere...

If you want a cable + microphone, this one is getting good reviews. I bought this one... but FYI, it took 3-4 weeks to ship because he's a 1-man operation and currently swamped with orders.

http://www.southbayriders.com/forums/showthread.php?t=119897

Another one that's used/recommended quite a bit:

http://www.amazon.com/Audio-Technica-ATR-3350-Omnidirectional-Condenser-Microphone/dp/B002HJ9PTO/ref=sr_1_1?ie=UTF8&qid=1337357850&sr=8-1

The disadvantage of the Audio-Technica is it's battery powered, so when the mic battery goes dead, your video clips won't have any audio. And there's no indicator to tell you when the battery's dead.

To plug in the microphone, you can either use the skeleton case or drill a hole in the water proof case.

[greatbuffalo]

http://pointofviewcameras.com/accessories/gopro

Lots and lots of stuff here.

External mic
http://pointofviewcameras.com/3-5mm-microphone.html

Skeleton case.
http://pointofviewcameras.com/gopro-hd-skeleton-quick-release-housing.html

[The Yeti]

I wish my Contour had and external mic jack. 

Apparently it can be done, but not without major surgery.

[JoniJo]

Great advise! Thanks folks. I think I'm going to try the Audio Technica and carry lots of little batteries.   
Cannot wait to see all of you!            JoniJo