If you're thinking about paying down your mortgage, see if you can cheaply refinance to a 15 year with a lower rate which is basically doing the same thing but doing it at your current 30 year rate. Well, I'm assuming you have a 30 year.
I've heard that making 14 payments a year at your 30 year rate will get your house paid off in 20. I'm sure you can afford a 15 year with change to spare.