I saw a poster lasgt night at what seems to be an amazing mobile offer so I thought I'd pass it on.
I believe the poster for Mucho Moblie says that up until the end of 2011 your can use their prepay service to call many overseas countries for free.
The only drawbacks I could see were that it's only the first 15 minutes are free so if you go over 16 mins you get charged (I guess quite a high rate) and of all the countries listed it did not include the USA.
I didn't have time to read the small print so there might be limitations to the number of calls you can make per day.
Anyhow it soinds like the introductory offer is pretty good. Not sure how much the SIM cards are but you normally get some free minutes included when you sign up for pre-pay networks.

www.muchomobile.ch

Cheers,
HB2

Hello,
I confirm Mucho mobile is a great offer to call outside of Switzerland. Actually for many countries you pay 0.19CHF flat. After 16 minutes you pay per minute, but still not that much (0.07CHF/min for Germany and Poland). Calling cellulars is also very cheap. My best for Canada as well.
I bought mine at Post. Cheap and easy. They use Swisscom so the quality is tip top.
Cicc'

Hi,
Just a quick note of warning, we had a Mucho pre-paid card, all was OK, until 6 months. If you do not USE the card or top it up, then all your credit will be LOST.

Just check the small print. We have switched to Yallo pre paid, no timeout problems.

Bummer, but i think this applies to any prepay SIM card not just Mucho. Don't leave your Yallo or any other prepay number unused for 6 months either.

I think if you want to keep prepay SIMs working you can just dial any number and get a ringtone and hang up without connecting, then your six months extention restarts again. Same if you answer a call on your prepay number.
Maybe someone who works in mobile telecoms can confirm this?