Let's face it: the built-in speakers on our laptops don't do justice to music, but it isn't always practical to plug in a set of speakers when we want high-quality sound, or to dig out a pair of headphones. Enter Apple's little-known but much loved Airport Express, something that you'll wonder how you lived without.

The Airport Express is a little white box, about the size of a MacBook Pro power adapter. You plug it into a wall socket, and go through some simple configuration to have it join your existing wireless network (it can also be used as a portable base station in a pinch or on the go). Here's where the magic happens: when you plug a set of speakers into the unit's 1/8" audio jack, the Airport Express shows up in iTunes on your computer and lets you wirelessly beam your music to it. For extra credit, iTunes can switch between destinations (say, one in your kitchen and one in your living room) or even send the same audio to multiple units, perfectly synchronized.

For more control, there are third party applications like Airfoil that let you change volume on a per-destination basis, or send audio from other applications on your Mac. If you love music, the $99 Airport Express is worth a look.