Building a Mobile WLAN Access Point
Problem: you want to share a fixed-line or mobile Internet connection via standard 802.11b/g technology. For example, you might want to share an Internet connection at a trade show, or create an ad hoc wireless network for an outdoor meeting.
General Purpose Mobile Access Point
Solution: easy (brain-dead simple with Mac OS X), just configure your PC to share its Internet connection via wireless. Wei-Meng Lee describes how to do this in Panther.
Not much to describe or discuss here. If your OS allows Internet connection sharing via 802.11b/g, this is pretty easy to set up. So if you’ve got a wired Ethernet connection at your tradeshow booth, but no standalone WLAN router, this is simple enough to set up.
Cellular To WLAN Mobile Access Point
If your laptop has a cellular modem and allows Internet connection sharing via 802.11b/g (again this is easy to configure on a Mac), use the trick above to do this.
EVDO:WiFi Mobile Access Point
In this helpful article, Tor Amundson describes how to build a self-contained cellular (1xRTT/EVDO) to 802.11b wireless access point. Very nifty. Hopefully this type of appliance will become standard issue in the next couple of years. I can think of a lot of situations where something like this would be really useful.