I'll second the vote for Tecnu. I carry an extra bottle in my BOB.

I get a rash if I just look at poison ivy, and Tecnu does a great job for me. It might work for you as well, 91gdub.

I saw it on the web for $15.00, but last fall I picked it up for $10.00 at the local drugstore if I remember correctly. It might have been an end of season sale or something.