http://www.covertcall.com
You can use this service to spoof your callerid.
So you can call someone and make the phone number show up as the presidents , or paris hilton.
And as recently noted on the news if you call up most cell phones and make the caller id the same number as the phone your calling you will get into their voicemail..
A free demo is provided for a sample, simple enter your telephone number and signup then once your inside simply enter a number to spoof and the system will call you from whatever number you entered.
Payments can be made using paypal..
Enjoy