Did you work two jobs last year? There is a chance you are due back additional taxes! When combined Social Security (FICA) taxes withheld exceed $6,621.60, any excess paid will be refunded on your federal tax return. See this article about it:
http://online.wsj.com/article/SB10001424052748703843004576140972174233398.html
If you have excess social security withheld you probably have excess State Disability withheld, too. SDI withheld in excess of $1026.48 is refundable on your state income tax return. See this from the Franchise Tax Board:
http://www.ftb.ca.gov/individuals/faq/ivr/227.shtml
Remember to bring this up with your tax preparer so you can get the maximum back. (If your tax preparer is me I will know this when I see your W2s).