Status of roads @Aug-09
The "Inland" road has now been sealed for about 5 years, and thus you can get to Cooktown easily. The "Coastal" road still requires a 4-wheel drive (not an all-wheel drive). Although this is called Coastal, it doesn't really follow the coast, and there are no views. It is only worth doing if you are already in Cape Trib, because the way around is quite long - you have to go back almost to Port Douglas.
Skytrains offers quite affordable flights between Cairns and Cooktown. The 45 minute flight is truly worth it. The views to Great Barrier Reef are stunning!