There are few applications that are indispensable. This may well be one of them.
Quoth the site:
This software allows your Windows computer to go online by connecting to your Windows Mobile Phone through the ActiveSync cable/dock, Bluetooth or InfraRed. If you own a Treo 700w/700wx, Treo 750, Motorola Q, PPC/XV 6700/6800, Samsung I730/I830, T-Mobile MDA, Cingular 8125/8525 Windows Mobile phone with a data plan, PdaNet will make it your high speed wireless Internet Service for your laptop/desktop computer instantly - no extra hardware or setup necessary, no need to kill ActiveSync or perform any tricky hacking to your device. Check out what Treo users say about PdaNet.
(Yes, no wifi on the delightful ride home today