It looks like Hong Kong's Mass Transit Railway (MTR) is the latest to hop on the high-speed wireless (in more ways than one) bandwagon. with it now set to offer WiFi in both its trains and train stations. Apparently, the trains will be outfitted with receivers to pull down 3.5G signals from transmitters in the tunnels, which then gets turned around into plain old WiFi for the passengers on board. While that convenience won't come free, it will be fairly reasonable, costing passengers HK$20 (or $2.50) a day for unlimited use.
[Via Akihabara News