Like most others here I've lost a good few $$$$ on European SIM cards...
Now I just grab a local country SIM card and, if I'm not planning another visit in 12 months, sell the SIM card on eBay - there's a ready market on the UK eBay site...
I also use the Skype WiFi Connect service - costs about 10 cents a minute on most public networks around the world and allows outbound calls to most destinations for peanuts...
Hope this info helps... Steve
PS - if anyone wants UK SIM cards, just ask...
[size=2]Steve Gold
PO Box 1014, Sheffield S10 5YG, UK
Home mobie: Telefonica O2
Other UK mobiles: 3, Vodafone, Virgin
Foreign SIMs: Toggle (multi); Germany (Fonic); Poland (Orange PL);
Skype: stevewgold