Vodafone Italy has a new add-on for data roaming (phone use, not usb dongle).
It's called Passport Mobile Internet and it gives you 100Mb a day for just 2€ till May 31 2011.
After May 31 you get 50Mb a day for 2€ plus 1,5€ of standard national tariff if you don't have any national data option on your sim.
I think it's a pretty good deal for short trips in Europe.
