Careful with the IUD route. My exwife was researching that because the hormones in the pill were fucking up her moods so bad. One of the main conditions to getting an IUD is if you've already been pregnant/given birth.

Depending on whether you use the hormone based one or the copper one it can last 5-10yrs respectively. Insertion and removal are EXPENSIVE though. $200-600 for the whole deal. $200-300 to remove.

Not good for women with heavy flows or bad cramps or who get lots of PIDs.
Here's a link for about who should get it and who shouldn't.

http://www.engenderhealth.org/wh/fp/ciud1.html