I think "straightening perms" use heat & aren't the best for your hair but you don't have to do it often.

Here's a link to a not heat hair straightener on ebay, but chemicals seem worse: http://tinyurl.com/295lxu

Hey, welcome to mosio!!!

Hair is protein and curls because of quaternary structures. Denaturing these proteins (breaking some bonds) would cause them to straighten. Heat does this the cheapest; acids, bases, and solvents also work. Ask a hair stylist :-)