Just got back from a couple of weeks abroad (UK, FR, NL) and checked my data use. I was worried I'd get socked with a $300+ roaming data charge on top of the phone bill like my bother with the iPhone did. I used zero kb for $0.00. I wasn't about to sign up for AT&T's AT&T International - Wireless from AT&T at $24.95/month for 20mb ... and they wanted a year commitment even though i'd only need it for one billing period. Anyway, it was a vacation so access to email and the web would be fine with local wifi. I made sure that under Settings>Wireless & Networks>Mobile Networks Data Roaming was NOT checked ... ever. I also only checked Data Enabled only when connected to a WiFi hot spot. I did speak with the AT&T rep prior to leaving but he wasn't sure if an unlocked Nexus One would automatically connect or not without the global data plan. He assured me that AT&T branded phones without the world plan would not even connect, let alone use data. The phone connected to the European networks flawlessly, although with the GPS off, I had to manually set the time zone. I would have thought that the network could determine location by the towers and adjust time accordingly, but no big hassle. And texts were still working fine. WiFI was everywhere, however most of the time it was not free.