If you don't want your number being passed via ANI to the 800 number owner and don't want it to appear on their monthly 800 bill statement, simply use your local "0" operator to place the 1-800 call for you, it's free. Simply state "Operator, I'm having problems dailing this call..etc.." Readers of comp.dcom.telecom and 2600 magazine already know about this neat little trick. You can prove it to yourself by calling Full Disclosure's 800 ANI Demo line (800-235-1414) first without using an operator, and then with an operator and compare the results.
I just tried this, both ways, and got my own home phone number repeated to me, both times. Maybe they fixed this "bug"? Happy Hunting, -Chris <cdodhner@indirect.com> PGP public key available upon request.