I got the single PCMCIA socket sleeve for my iPAQ (after waiting for 2 months for my dual PCMCIA socket sleeve, grrr), and got 802.11 wireless networking working. Pretty easy, actually - got the drivers off of wavelan.com, installed them, and set up the crypto. The only downside is that the iPAQ is pretty flaky about being turned off with the card still in the socket. Buggy driver, I expect. I suppose that'll go away when I finally install Linux on the thing.
In the meantime, I've been having fun with my home mp3 server. I whipped up a really quick and dirty PHP-based server control system. Now I can walk around the house and control my mp3 server (it's connected to the stereo) with the iPAQ web browser. For that matter, I can control the server with any old web browser. :-)
It's so nice to be able to do little hacks like this every once in a while. Now if I could just get my thinkpad IR port to talk with my stereo, I'd be in heaven!