The best phone number to use (for a fake phone number) is your area code plus 555-XXXX. Any series of the last four digits will work. 555 is the universal prefix that all movies use for fake numbers – plus, using this number means no one else will inadvertently get your telemarketing calls.

With telemarketers – I always ask if they will take me off their list if I get a call from them. This doubles the effectiveness of the Do Not Call list.