If you ask for reimbursement for mileage for business or medical purposes, then you will be interested to learn that the IRS recently released the 2012 Standard Mileage Rates. They typically release these figures earlier - late November or early December. I look for these rates because my spouse does get mileage reimbursements and also because we defer money into a FSA and reclaim the mileage throughout the year. Open Season for us ended on Monday, so I wish they'd have released these rates earlier so people could make better informed decisions regarding Flexible Spending elections.
However, the rates are pretty much unchanged. As of the new year, the standard mileage rates will be:
55.5 cents per mile (business miles you drive) --> unchanged from July, when they adjusted this rate up
23 cents per mile (medical/moving reasons) --> up half a cent from 2011 standard mileage rate
14 cents per mile (miles you drive on behalf of a charitable org) --> this rate is fixed by Congress and hasn't changed in several years).
So really, not a big change from 2011 to 2012 with these rates. If you're looking for the IRS' 2011 standard mileage rates rates, please view the IRS's handy bulletin outlining the changes mid-year. Remember, there was a mid-year jump for business, medical, and moving so the rates are different from January - June 30 and July 31-December 31.