Get all the details and compare carefully before making a decision.
FYI - I am in the RE profession, so we get this ? a lot. As stated by the lending professionals we deal closely with - it is generally not beneficial until the rate drops two (or more) points below what you are currently financed out - to average the difference of costs of 're-fi' into the equation - and to make it worthwhile for you. FYI - as an aside - we are in a similar situation - lived here 3 years, financed @ 6.725 - You don't have a bad rate, and it'll be hard to refinance low enough to make it worth your while. Maybe you wish to consider prepayments on your principal - which will significantly decrease the amount of interest paid on your loan. You can do a search for a mortgage amoritization calculator, (there are many available online) - and this will allow you to see your interest savings in details, varied by the xtra principal you choose to pay.
Hope this helps!