The new PCMag.com Wireless Center has a free utility called WiNc from Cirond that includes some of the functionality of NetStumbler and can also function as a replacement for WinXP’s wireless connection manager. Check out Cirond’s supported hardware list before trying out the utility. Also note that you must get it from the PCMag.com site within the next two weeks and not from the Cirond site. After two weeks the program costs $20. I think that means picking it up from PCMag.com will keep it free forever. You can find more about it and download the program here). There are versions for PocketPC 2002 and 2003, too.
The utilities that come with the Orinoco card are pretty good — it can scan for access but it doesn’t record — and if you don’t have an Orinoco, you’re SOL.