[bbob]

You can try to do it yourself

at sipgate.de you can get a free did voip number.
Then using pbxes.com or simualr system you could setup a callforward system.

You call your own number, give a pincode and you will get a dialtone to dial the number you want.

Onlt problem with pbxes is that freecalls still don't seem to work because of some ip problems. That said you can still use your mobile to make cheap calls outside germany this way.

If you have a regular number i doubt that it will ever get blocked but a carries. I did this when I was in the USa last year. Used my did number there to call the number and than call europe for low voicetrading/betamax rates.