Refinancing is not the only way to decrease the term of your mortgage. By paying a little extra on principal each month, you will pay off the loan sooner and reduce the term of your loan. For example, adding $50 each month to your principal payment on the 30-year loan above reduces the term by 3 years and saves you more than $27,000 in interest costs.
It's better to follow the 2% Rule which suggests that you can enjoy the benefits of a home refinance if your mortgage refinance rate is 2% lower than that on your current loan. The interest savings will help you recoup the costs you've paid for the new loan provided you stay in the property for a certain period of time (break-even period). However, there are no-cost as well as low-cost refinance loans wherein the costs are included into the loan. But you can expect comparatively higher rates on such loans. Moreover, these loans are limited when the market is in a credit crunch.
Before you refinance a loan, make sure that you carefully analyze any fees that your lender is including on the loan. The Department of Housing and Urban Development can provide you with a list of standard fees. Use it to make sure that your lender isn't tacking on anything extravagant. And by all means, compare their fees with other lenders in the market.
Refinancing may not be that useful if you have already used up 90% or more of your home value in taking out a mortgage or any home equity loan. You won't be able to get the best rates available in the market as when you refinance a 90% LTV loan, you will probably require a loan of that value or higher. This will be quite closer to being a 100% financing option and hence mortgage refinance rates will be comparatively higher. Moreover, 100% loans are hardly available in times of mortgage market crisis.