Anonymous VoIP Calling
There are several applications that can help you shield your phone numbers, whether cell, land line or VoIP.
For call handling and call blocking, take a look at Jaxtr. This service gives you a Jaxtr URL. On someone’s Jaxtr URL you can enter you phone number and Jaxtr calls you and the other person for the cost of a local call.
Craigsnumber is a free service that generates a phone number where people can reach you. Before they can connect, however, users will need to leave a short message. Once you hear the message you can choose to connect with the caller or not.
For premium call blocking (maybe your VoIP number is already public) check out Privacy Corps. This $100 device can block up to 175 numbers or even entire area codes or area codes + prefixes.