Clint- you should refinance right now, and specifically this weekend.
You don't have to pay PMI if you have less than 20% equity, the better option is lender paid mortgage insurance. This is where the lender pays a 1-time premium to cover your mortgage insurance at settlement. This can be built into your rate. With 5.75% you can save significant money going to near-current rates and even look at a no-cost refinance where all of your 1-time closing costs are covered.
Rates are at the lowest point for 2011, the importance of making a move this weekend is that the US debt downgrade announced last night will very likely make mortgage rates go higher Monday morning.
I am working all weekend and would be happy to go over numbers with you. Feel free to contact me 301-585-7283.