Lowest ever, $19 off Apple Store price
If you want to stream music with ease from your smartphone or computer, or if you want to be able to set up a router in a matter of minutes, check out the deal Amazon's got on the AirPort Express today. $79.99, free shipping: Apple AirPort Express Base Station WiFi Router - MC414LL/A
You can stream to it with AirPlay over WiFi or Ethernet, and you can configure it to repeat a wireless signal, etc. It's versatile without any crazy hacks or third party firmware loads.