I've been touring with a cast-iron skillet for about 3 years now. Started with an 8" (3.5 lbs) but switched to a 9" (4.5 lbs) for my cross-country trip. Never regretted it. I don't like burned food, and the cast-iron is FAR more versatile than titanium, aluminum, or even stainless. Plus after 6 months on the road it becomes naturally non-stick.
Yeah, it weighs as much as the entire rest of my camp kitchen, including fuel - but what fun is touring without at least one luxury item?
I should add that I've used the pan to cook pancakes on overnight outings on Cycle Wild camping trips (
www.cyclewild.org), as well as making a sort of "hamburger helper" on tour (1lb ground beef, 1 cup macaroni noodles, 1 pkg stroganoff or meatloaf seasoning, fill most of pan w/ water, cook 10 minutes). I use it with a MSR Whisperlite International stove. Great for cooking bacon, eggs, or anything else which might be prone to burn in thinner pans (i.e. everything but water).