Cell phone numbers become available and legal for telemarketers to call this month. (Good to know congress is looking out for your interests). When they call, you will get charged your normal rates for minutes.
To avoid them waisting your time and money, add your cell phone number to the National Do Not Call Registry. To do this call 1-888-382-1222 from the number you wish to add. The whole process takes about 20 seconds.
Then, 31 days after you have registered, if you receive any telemarketer calls at that number you can file a complaint with the FTC and the offending caller can receive a $500 fine, per call.