Chemically straightened hair?

I hate my hair. It's definitely the thing that will make it hard to pass as a girl if I can't get it straight (I don't often see girls with afros).

I was talking to some friends today, and they told me I could get my hair chemically straightened. I read some stuff on the interwebz, and a lot of people are saying it's a bad idea, and others are saying it's a great idea and you should do it. It's not so much that I just want straight hair, I just don't want thick, curly hair that just grows out into an afro.