Cnet has an article about bluesnarfing. Several cell phones, especially Nokia hand sets are susceptible to an attack via a bluetooth hole. The hole makes certain handsets open to allowing someone to get in, copy the address book and phone numbers and leave no evidence of the attack behind.
According to the article Nokia is taking a head-in-sand approach to the problem. They are not planning to release an upgrade because of the "limited" number of handsets impacted. Instead they suggest that people turn off bluetooth all together when in public places or put the phone in invisible mode (though this does not prevent bluesnarfing). Read more about How safe is your phone book