Heather and I recently took a trip to Russia in the early spring. I wanted to be able to have working GPS and internet while we were there. AT&T offered no roaming plan and it looked like rates were going to be around 5$USD per minute and unknown rate for data usage. So what did I do? I hacked my iphone and
installed yellow snow.
For about 20USD$ Heather, using her Russian skills, bought this Beeline sim card at a telecom shop. It was a prepaid card that allowed me to make 1 quick phone call and all the internet I could use on our 10 day trip. I didn't track KB usage, but I liberally used maps and checked e-mail. We even posted a few photos to facebook while we were walking around. We ran out of our prepaid allotment at the airport on the flight home, but refill stations were everywhere if you need more of an internet fix.
The documentation was unclear as to whether this would work, but this nice little hack saved us a couple hundred dollars of cell phone bills.
Moscow had great edge coverage. The sales reps in Moscow said there was no 3g coverage anywhere in the country but we found St. Petersburg had great 3g coverage. We even made a few voip calls over the 3g with siphone.