There's an article on Wired on MSN with help on stumping would-be identity thieves:

"... several tools are available now to individuals that reduce their risk of identity theft, according to Hoofnagle and Tom Fragala, a volunteer with the Identity Theft Resource Center who is working on a free, do-it-yourself credit-monitoring and identity-theft recovery service."

  • Opt out of credit card offerings by calling 888-5OPTOUT (888-567-8688). 
  • Check your credit reports frequently with a free credit report once a year.
  • Put a one-year credit alert on your credit reports.
  • Review your finance-related statements monthly. 
  • Place a 90-day fraud alert on your credit reports - I've found that some credit agencies will extend thsi to a year if you have been victimized.
  • If you have been a victim of identity theft, file a police report and contact the credit reporting agencies.
  • Don't use your full Social Security number as your ID, and be careful where and when you provide the full number.