I finally decided to give wireles a shot, and went with the D-Link DI-624 access point and a DWL-G650 AirPlus PCMCIA adapter on XP Pro. Here is my experience, briefly...
Access point + adapter were operating in the 'up to 54mbps mode'. A free firmware update for the access point and a new driver are available to double the throughput (in theory, I guess). My adapter is now using driver version 2.40 (XTreme 108 I think they call it).
I stumbled upon netstumbler, and thought I'd give it a peek. I only quickly scanned over the forums and Readme. I was a little unclear as to whether or my specific hardware configuration would work, but no harm in tinkering, and if it didn't... then I'd just buy something that is known to work and is officially supported, because wardriving sounded very interesting!
So, I installed NetStumbler and fired it up. Immediately it picked up my access point (unencrypted at the time!). The only columns left blank were name, vendor, latitude/ longitude. Graphs were working nicely. Just so happens that I needed to pick up a pizza about 15 miles away just as I was reading more of the Readme. So, I carried my Latitude with me!
As soon as I got out of the driveway, Net Stumbler alarmed me that it had detected an access point. Nice! I figured I just got lucky and wouldnt need to sink any additional money in to supported adapters and such. Suddenly, though, Net Stumbler closed. I tried firing it back up and nothing. Several more times, nothing.
Then rebooted my laptop, fired up Net Stumbler again. Yay its back up. BLAU! Another access point (by this time I was driving along side an air force base, they are running an Aironet access point
Same thing happened again. Net Stumbler crashed, it wouldnt come back up until after a reboot.
And well, that is pretty much where I left off with it. I perused the forums in search of answers. IMO you are better off going with something that is supported and proven. For $100 bucks sounds like you can get everything you need with minimal problems (external antenna + supported adapter).
So, my advice as a noob just getting in to wardriving, get something proven to work. Threads like this drive me up the WALL. It is UNSUPPORTED. If someone gets it working, great. Read what they have to say about how they made it work. If you can't find anything, you probably have not looked hard enough. If you STILL can't find anything, just remember... it is unsupported and you will save yourself some troubles by simply getting something that IS supported!