So, what kind of data speed do you get when you're on WiFi?
I did some benchmarking of 3G and WiFi data speeds out of curiosity using the Xtreme Labs speed test app. On 3G I see data rates ranging mostly from 300 - 1300 Kbps (with min/max of 90 / 1900 Kbps). I'm on T-mobile.
On WiFi I get consistent speeds of around 450-550 Kbps. I tested it on two WiFi networks (802.11g/n, and the other is g-only; both with WEP). It's not limited by the network, as the house has Comcast; speed tests from a WiFi PC show 12Mbps repeatably (via both WiFi's).
I was expecting WiFi to be faster than 3G... At least to be as fast as the fastest 3G results.