Airport Express Is Amazing
My in-laws gave me an Apple Airport Express for my birthday.

Let me tell you - this device is amazing.
First of all, it’s compact. You could very easily take this on trips, etc.
It’s a wireless access point. Apple’s WAP devices work very well in my experience. That being said, I’m not using my Airport Express as a WAP. Why you ask? I already have a Linksys WAP and router that works just fine. Airport Express can be used to extend an exisiting wireless network. The catch is that the WAP must be an Apple Airport. So that won’t work with my Linksys. Not a big deal for me though.
What i wanted this device for is AirTunes. Simply put - AirTunes allows you to stream your iTunes music library through the Airport Express to your stereo connected via a standard 1/8″ stereo port. This is so freaking cool. I know this isn’t the first device to do this, but none have done it with the style that Apple has.
My Airport Express is a wireless client - no ethernet wires. I set it up that way since my stereo is downstairs and my Linksys WAP is upstairs. You could very well use a CAT5 cable to connect the Airport Express to your network.
I’m VERY pleased with this thing. If you are as addicted to music as I am, I suggest you go purchase an Airport Express.