If you do not currently participate in a plan at your work, you can contribute up to $5,000/year to your IRA and deduct the contributions from your income tax; $4,000 plus a $1000 "Catch-up" contribution because you are older then 50. In 2008 it goes up to $6,000. If you are a participant in your company plan (Simple IRA, 401(K), 403(B), etc.) then there is no deduction allowed for traditional IRA contributions. In this case, a Roth IRA might make more sense. (
http://www.investopedia.com/terms/r/rothira.asp )Using an IRA is important because of the tax deferral. Not having to pay taxes on your gains helps the savings add up faster. $6,000 added annually to an IRA invested in such a way that it had an average return of 8% (Which is easy to do with a conservative allocation) would grow to just under $94,000 in ten years.
Here is a great website with all sorts of financial calculators:
www.fincalc.com
When the page opens, click on "ConsumerCalcs" on the left under "Content".
When that page opens, scroll about halfway down and you will see on the right a "Home & Mortgage" section. There is a calculator there that can help you determine the tax ramifications of your mortgage and therefore whether or not it is smarter to pay it off sooner or continue with the payment schedule.
FinCalc also has many other useful financial calculators. I highly recommend the site as well as www.investopedia.com as a great resource for understanding investing terminology.
Best of luck!