That's right OA,
Worked straight out of the box. Easy enough to find a picture of it. The 'cigarette packet' has two or three prongs on one end corner for connection to the mains. For road warriors the corner removes so you can slot in the correct prongs for the power system in the whichever part of the world you find yourself.
Plug in and at the bottom you have three ports. Ethernet, usb and stereo mini jack. Finally there is a LED window facing the room cycling between yellow and green to let you know when connected and working/transmitting.
In addition to creating an instant wireless network with remote printing/scannning or whatever you've got usb wise there's one other aspect that might appeal with regard to your thoughts on extending range around the home.
For music fans the software adds a new function to iTunes ( comes with all Macs but a free download for you PC people) which gives you a drop down choice. Normal output or the names of any wireless networks available. Select the network name and the music is silenced on your system and piped to the mini jack on the Airport Express. Pop it into a socket near your stereo, connect a lead to an aux input and voila.
We really rather like it!
Regards again
Rob