Stand it up or lay it down -- the Wii console's slot-loading drive will work fine either way.
Measuring a little less than three stacked DVD cases, it should also fit easily in any entertainment center.
Just make sure you find room for the included sensor bar, which enables the Wii controller to work, and
needs to be set horizontally above or below your TV. A concealed slot on the front connects regular SD
digital storage cards, and the Wii can also handle Nintendo GameCube controllers, memory cards for
saved games, USB devices, or connect to your wireless network. - Source: Yahoo (http://wii.yahoo.com/info)