Ben, I got my cat used to a leash and harness but it is a very slow process. Don't ask me why I did this because she never goes outside.. But anyway, the first thing I did was I kept putting the harness next to her while she was resting or sleeping. Then I'd put it on top of her, not actually hooking it on her but just laying it on her body. After she felt comfortable with this, I put the harness on and let her run around. It was really awkward for her for a little while but she got used to it. The last step was attaching the leash and walking her around the house.

I agree about not taking the cat on a camping trip. It really seems like a great idea but there'd be soo many risks. I never even let my cat in the front yard because I think there's enough risks there.

Good luck.