Jason Snell about AirPort Express:
Now some more general advice. First, even if you think you’re a really, really geeky Mac user, don’t start with the AirPort Admin Utility. Apple has really done a remarkable job with the AirPort Express Assistant, and you should give it a try. Yes, it’s a wizard-style interface — what’s the challenge in that? — but when you’re in a situation where you’re configuring two wireless devices at once (for example, setting up a wireless relay from one AirPort Extreme or Express to another one), using the AirPort Admin Utility can get really hairy. In contrast, the Assistant is a breeze.
OK, I think I’m a really, really geeky Mac user. Send me an AirPort Express and I’ll show you how I configure it and my AirPort Extreme Base Station for bridging, both at once, using the AirPort Admin Utility. If I succeed in less than three hours, I’ll keep the AirPort Express. :D
Update (April 20, 2005): By the way, after recently buying an AirPort Express, I did just that, and in much less than three hours.