Used to be you could get it automatically cancelled when your loan to value reached 80%. With payments and strong appreciation if you bought right you could get there relatively quickly. Just about a year ago they changed the rules, now PMI stays on the loan for it's life. You have to refinance to get out of PMI, which does nothing for you, it insures the lender, not you. Money down a rathole. Do what you can to refi as soon as you can if the numbers make sense. Using your PMI premium to pay for principal and interest beats the heck out of paying for a policy that you get no benefit from.

http://mynorthwest.com/800/2207994/FHA-no-longer-will-drop-mortgage-insurance-premiums