I've been using the service for a while. Where it works, it works great. But unless you're in a anointed Starbucks or an airport in doesn't work at all. In my case, it's almost cost free. I have a built in 11b device. There is no card or antenna sticking out of my computer. If you have to buy an 11b card, it's more to think about. You lose your card slot and you have an antenna sticking out of the machine. I'm not sure the marginal benefit of the service is worth the inconvenience.

Wi-fi has got to be an interim solution. Obviously, wireless service available virtually everywhere and at reasonable speeds is the ultimate solution.

While I don't have one, friends who do rave about their Blackberry units. It's secret is that it is always on and receiving Email so when you want your Email you get it immediately. You don't have to wait an eternity for your hand held to receive your messages.