iPhone 3G Study Shows Regional Differences in Speed
When broken down by country, they found that participants in Australia had the slowest average 3G download speeds at 759 Kbps.
Meanwhile, results from individual carriers showed that European T-Mobile had the fastest speeds at 1,822 Kbps, followed by Canada (both Rogers and Fido) at 1,330 Kbps. U.S. AT&T customers found themselves in 3rd place, tied with Telstra, Telia and Softbank at an average speed of 990 Kbps.
Wired's results provides the findings in more detail.