Try the ZyXEL G-202. But DO NOT use the driver that Vista will attempt to
load. It won't work (causes BSODs). Get the driver off of the ZyXEL web site.
The driver works on both XP and Vista. Don't install the ZyXEL USB device
utility software, just the driver. Let Windows XP or Vista manage the device,
and it works fine.

This is a wireless G device that can also be used as an access point from a
computer hooked to the internet. A nice feature for "group" mobile
situations. It also supports WPA/WPA2 and a few other more advanced features
for increased signal strength and quality of connection on VOIP and
multimedia applications.

Tigerdirect currently offers this device for $20.00. A very good price for
a USB wireless device in any event, let alone Vista certified.