Don't we always want what we can't have? Curly-haired girls pine for glossy, swingy straight locks, while those with pin-straight manes long for the body, texture, and versatility of curls.
If you decide to try a straight style, there are three types of treatments you can choose from. The strongest are sodium hydroxide and guanidine hydroxide (aka "no-lye"), which break down the hair cuticle so that it softens and can be relaxed internally. Because both of these can be drying, they are only recommended for thick, coarse hair. A gentler alternative is ammonium thioglycolate (the same super-smelly ingredient used in perms). This is less effective, but it's also less damaging to your hair.
Professional straightening, while costly, is the safest option because of the chemicals involved. If you do decide to go the at-home route, I have a couple product suggestions, so read more.
One option that is getting rave reviews from users is the PhytoSpecific Relaxer 2 ($60). This is a guanidine hydroxide-based straightening kit that uses egg and a "soy complex" to straighten hair gently and effectively, while protecting against damage.
Revlon's Realistic Extra Conditioning Creme Relaxer System ($7) is a more affordable but slightly stronger option. It is sodium hydroxide-based, so it should be used only on the thickest and coarsest of hair.
Something to keep in mind is that relaxed hair needs extra taking care of. That means deep conditioning twice a week, using a leave-in conditioner, and laying off the highlights for at least two months. For those of you craving a change, this is a doable process, as long as you're committed to taking care of the results.