It does : 802.11g - theoretical top speed of 54Mbps, same as my laptop. However, the data flow speed is strangled due to the slowness of it's low power processor. The 3G also has 802.11g (54Mbps top whack) and it cannot achieve that speed either, but it is much closer to the speed of my laptop;
iPhone 3G (54g)
Laptop (54g)
For those confused about what the G is all about in iPhones - "2G" is a moniker given to the iPhone after the 3G was released to differentiate between the iPhone and the iPhone 3G. The "3G" points to it being able to run on the "3G" mobile/cellular networks. The "iPhone 2G" is actually just "the iPhone", and the iPhone 4G, as people are calling it, is actually just "iPhone 4" - the G means nothing.
Back in the day, Apple used to use a G, short for Gen/Generation, to note apart different models of the same thing. For example, the iPod - there was the iPod, then the iPod 2G = 2nd Generation iPod, then the 3rd Gen (iPod 3G) then the 4th Gen (iPod 4G) and so on. Some got halfway gens (iPod 5.5G). This was done away with when the iPod Classic (which would have been 6th Gen/6G) was released. The iPhone has never had these Gen names - 1st was iPhone (metal back, 4gb and 8gb), then the increased capacity iPhone (metal back, 8gb and 16gb) then the iPhone 3G (plastic black 8gb and 16gb, black and white) then the iPhone 3GS (S denotes "speed" as it had a faster processor - plastic back, 16gb and 32gb, white and black) then the now current iPhone 4 (glass back, 16gb and 32gb, black or white). So using the original Gen numbering system, the current iPhone 4 would actually be a 5th Gen, the 3GS would be 4th Gen, 3G, ironically, would be 3rd Gen, the "2G" would be 2nd Gen and the original incarnation wouldn't have a Gen number, but be given a retrospective 1st Gen.
I'll get my coat
