are there proxy servers for the telephone?

Question

is there a way to call someone and have a different phone number appear on their caller id?

Answer 1

Yes, except in the telephone world they're called diverters. Still, you don't get to decide what number shows up, just that a different number would appear as opposed to a blocked number, etc. Diverters are also useful over blocking caller ID as it will also mask ANI which is what toll free numbers use to identify you. If you use Asterisk with a SIP/IAX VoIP provider, you could make whatever number you want appear on people's caller ID's.

Answer 2

Not easily.