The first one we bought was a dud; it just wasn’t working, so I took it back to the Apple Store, who exchanged it without a problem, and I walked home with a new one ten minutes after I arrived at the store. Once we had a working model, the setup was less than ten minutes. It’s connected to the stereo receiver in our living room, using a standard RCA to Miniplug cable (the jack supports an optical connection as well). We took the option in the Airport Setup to have the Express dedicated to broadcasting music through the stereo— we could have also used it to expand the range of our Airport Base Station, but in a two bed room apartment, that seemed a little foolish. There’s also a USB port, so you could use the Keyspan Express Remote Control
Why do I like it? For the past couple of years, I’ve done most of my writing on my iBook, on the couch. With the Express, I can wirelessly play my iTunes music, both my purchased songs and songs I’ve ripped from CDs, through the stereo. That’s pretty nifty, but what’s even cooler, is that since my computer is authorized on my spouse’s iTunes account, I can also play his iTunes songs, remotely or locally. And we can stream music from any of our computers to the living rooms speakers.
Plus, since the Express is tiny, it’s exceedingly portable— we can take it with us on our next trip, and share an Ethernet connection wirelessly, with up to ten computers.
I can see myself borrowing the Airport Express to take to campus and plug in to the classroom, to be able to play through the built-in classroom AV system without having to arrange for an AV person to bring special equipment and string long annoying cables.
I bet Airport Expresses are going to be very, very popular in the dorms this fall.