Let the hive mind of Engadget get that for you.
"As someone who doesn't reside in the USA, I was wondering what would be the best way to get internet for my computer in the US for a couple of weeks? If it were Europe I know I'd look for some prepaid data. Is there anything similar offered by American carriers? A MiFi or a data SIM that I can tether from would work, but I'm trying to maintain a tight budget. Help!"
The G1 isn't so cheap in Europe, its right, you will get it for about 1 €, but here in Germany only with a 24-month contract, the cheapest costs 44,95 € (a.t.m. about 58 US-$), so it will cost over 2 years about 1080 € (1400 US-$). Then you can call cellphones (only T-Mobile) for "free" as long as you want, as well you can call the conventional telephone network, for all other connections you need to pay (as well you need to pay extra for SMS (out of the "T-Mobile Net" and MMS). So its not SO MUCH cheaper as in the US, it really depends on your use of the telephone and the package you choose ... for the smallest contract you need to pay about 775 US-$ (in Germany) plus the phone which costs then 77,50 US-$ ...
So its not such cheap, its like always here, you don't get (like in the US) about 500 or 1000 free minutes to use for cellphones or whatever, you have maybe here a flatrate, but only for T-Mobile and the conventional telephone network. And since I guess everybody has friends with o2 or vodafone (or other providers) you need to pay extra for each minute (exactly 0,29 EU-Cent --> about 38 US-Cent) ...