Julie,

I am really glad you put in the postscript. I have seen a lot of thes pay off your mortgage faster ideas, and to me, at the end of the day, hey all smell like the idea of having more taxes withheld from your paycheck so you can get more next April. It feels good in April, but it doesn't make much financial sense.

This is what i was going to write.
The pay-off-a-little-more-each-month fallacy has been around for a long time. The deal is that the numbers are big, so they are really impressive.

Yes. It builds equity faster. (But it's just converting your cash from a flexible form of equity into a less flexible form.)
Yes. You pay less interest over time. (But you lose opportunity to invest).
Yes, you pay off your house sooner. (How many of us will live in our house for 20+ years though?)

The right way to look at this is to consider the alternative uses of the extra money you would be putting into the equity.

For example, a 6% loan has an after tax 4% rate. Instead of putting the money into your house, why not put it into a SP500 index fund? It will get you 8% over time (5.33% after taxes). So by putting $1000 into your house, you lose $13.33 each year. Put it into the IRA that you haven't been funding and it looks even more attractive, because it is tax-deferred.

Alternatively, maybe ou take that round the world trip that you have always wanted to do, or invest in a good personal trainer to enhance your health. You can't put a value on those, but in any case, the pay off your mortgage faster idea is only for people who do not otherwise have the discipline to save in other ways.

It's kind of like the people who advocate extra withholding from their paycheck so they get more back in April.