Thanks again. Calling cards are interesting, but we'll have WiFi in our Condo, so longer calls will be placed by VoIP or by Callback (both through poivy.com). Actually Tuyo's $ .12/min for German landlines and $. 36/min for mobiles is too cheap to struggle with calling cards and I doubt they would be significantly cheaper.

I just use callback now myself. I have a Canadian DID through voip.ms that I call. It rings busy. It calls me back. It costs me 2.5 cents a minute net (US) to call North America. Europe is not much more.

But with callback you pay something for the incoming call, don't you? So in the case of Tuyo a callback would cost $ .10 for the incoming call + $ .025 for the callback, so $ .125 in total, which would be more expensive than a direct call with Tuyo ($ .10).

Another question came up to my mind, as I'm going to Cali in March: Is there any disadvantage for me if I activated my Tuyo SIMs with an address in NYC, so I get a NYC local number but used it elsewhere? Afaik the big US cellcos offer nationwide tariffs so there's no such thing like national roaming if you leave your home state, right?

No disadvantage to you whatsoever. Pretty much just about all cellphone plans include nationwide calling an usage. So you can call and use it from anywhere in the US and it will not cost you extra. Now, if you happen to have a NY number and have a friend in FL that does not have a nationwide plan on their mobile (highly unlikely) or home number, they will pay long distance to reach that number.

Well, I would just dial directly to call the US. To call Canada it would be cheaper to use Tuyo than to do my trick, but only barely (12.5 cents versus 11.5).

Since I already have a $110 US balance on my T-Mobile SIM, callback works well for me. And T-Mobile works here where I live, so I can keep the SIM active easily.

Can foreign credit cards be used to top-up a Tuyo SIM? I don't recall seeing Tuyo top-up in convenience store anywhere.

Thanks Vlad. I remember recharging a Cingular GoPhone SIM with a German credit card back in 2005, so I hope a ethno-brand like Tuyo will accept foreign cards, too. Anyway Tuyo's FAQs mention recharge cards to be available (http://www.tuyo.com/site/faq.aspx?fid=4).

Thanks for the tip I'm gonna buy Tuyo as well. Does anybody know if you need an American credit card to recharge. With T-Mobile it is, my dutch master cards did'n't work.

mastercard is not that populat in the USa. Try Visa card. I had an at&t card last week in the US and loaded it with my dutch visa card. No problems to do so.

My brother topped up his Tuyo card with his UK issued American Express. That was about 2 years ago. He called their customer service (free from the phone) to do it. I also believe you can register online. Call and sms detail is also online.