I'm sure there's a lot more qualified here than me but I have some experience with this. I wouldn't refinance unless I could get 2-3% better interest rate. The closing costs are just too high. Make arrangements with your lender to do an automatic withdrawal for your payment each month and increase the amount your paying by whatever you feel comfortable with. They will tell you how much you will shorten your loan period. I'd talk to your lender and let them know what you want to do and they may work with you. Mention that you are shopping around too. That will make them more eager to work with you.

jmlane