In Amsterdam last week, I purchased a 10-euro SIM card and used it in my loaner N900 to connect to T-Mobile Internet when wifi was not available to me (eg, at the Hotel Ibis).

I accessed my Skype account and called my home phone in New Jersey. Everything worked fine, except nobody was home so I ended up talking with the answering machine.

Maybe this doesn't qualify as a connected phone call, since it was a machine and not a person that answered, but the cost and quality were all fine at my end.

Roger S