Fellow Glenn, the InstaPundit, joins in on the EVDO debate as a real user: We share a name and a political viewpoint--not in the red versus blue state sense, but around EVDO and Wi-Fi. Glenn brings perspective as a Verizon Wireless EVDO user and as an enthusiastic employer of Wi-Fi as well. Glenn thinks that Wi-Fi is a bottom-up phenomenon that has different characteristics than a top-down cellular network. He also points out good issues about battery life.
If you can't use EVDO for more than a couple of hours without recharging, then you need an electrical outlet. Which means you can probably find Wi-Fi near that electrical outlet.