Hey Jeff,
I was looking to hunt Kauai when my wife and I visited this past February. I was able to get my hunters safety permit and would have been able to get a license....but someone from the Hawaii DNR got in touch w/ my wife first.
The terrain is very rugged and steep. If you've got someone who knows the area(s) that is a big plus. If you're hunting alone in areas that you're not familiar with, you can, fairly easily, walk right off a cliff.
I'll be visiting the Big Island in '09 and I WILL be hunting. If I go back to Kauai, I will hunt there as well, but I'll only do so with someone who is familiar with the area(s) being hunted.
FWIW, my wife and I saw pigs while hiking. There were LOTS of pigs. Didn't seem too hard to bump into on the hiking trails. We saw some goats too, and got the ubiquitous "goat shot" at the Waimea lookout...I think those goats walk out onto the ridge at sunup and return at sundown.
Have a great time and hunt if you can.
homebru aka nathan