I'd put them in sixer packs wrapped in crinkled up newspaper to keep them from breaking/clanking the entire trip. As for being heavy think about how damn hard it is to lift up a full carboy. Probably about the same weight when it's bottled.
Most state parks and campgrounds really don't want you to have glass containers though so don't let the park ranger see them or he might be inclined to legally steal all of your homebrew.
Yeah, makes sense. I want to figure out how many of these I can take ahead of time, weight-wise. I'm thinking 18. I have some great beer drinking friends back home in Missouri and I want to find a way to bring my beer to them.