I recently went on vacation to Italy and temporarily switched to Verizon's international data plan so I could access the Internet on my Storm. It actually worked quite well and the GPS certainly came in handy!
I noticed that my Storm would frequently switch between networks (sometimes while sitting still in my hotel room!) so I decided to snap some photos. It was cool to see it switch between TIM, Vodafone, and Wind SpA as well as between EDGE and 3G (with the Blackberry symbol!)
The international plan was about an extra $25. Totally worth it if you figure in how much you'd pay for wi-fi per hour on a laptop.
For weather, I actually use the BB web signal from Accuweather (available via mobile.blackberry.com). It doesn't eat up as much memory as it's basically just an icon that gets updated when the web signal is pushed to the phone. Pretty cool
I too would like to know how much it cost you to arrange this, was it difficult to set up etc. Did you have to talk to VZW Service or go to a store?
Was there much difference between $ for phone coverage with or without data pckg?
Finally, were you able to use any of the GPS programs there (BB Maps vs. GMaps)
Inquiring minds.....