The last time I looked at a device that bridged an EVDO modem and a Wi-Fi hot spot they were about the size of a small commercial router and needed to be plugged into the wall. This wasn't that long ago. Two years maybe?
CradlePoint has just introduced the PHS300, a pocket-sized unit that does the same thing—make the EVDO from a 3G-capable device, like a USB stick or compatible phone, into something you can easily connect to with any device that uses Wi-Fi. And it's battery powered. (Although it can plug into a wall, too, of course.)
That's about all there is to it, but I'm just shocked how small they've gotten while I wasn't looking. It wasn't that long ago that a similar project took a whole backpack.
The PHS300 is $180. (And you'll need to buy an EVDO device and subscribe to a data plan, of course.) I want one badly, but I figure if I just wait another couple of years this will just be integrated into our phones.
CradlePoint introduces battery powered ‘Personal WiFi Hotspot” [EVDOinfo.com via Engadget]