But what about devices like the Xbox 360 or your trusty old Playstation 2? Are you stuck stringing ugly network cables all over your house to get them online since they don't have wifi?
Nope! In fact, you've got two good options for connecting items like these.
One option is to use a wireless bridge like the Asus WL-330gE or Dlink's DWL-G730AP. In simple terms, a wireless bridge takes a cabled connection and translates it into a wireless one -- letting wired-only devices communicate with your router just like they were wifi-capable. Wireless bridges do require some configuring to make them work, which is usually done via software on a CD that's included in the kit.
Sometimes, however, wireless isn't the way to go. Radio interference from other electronics, metal construction, distance, and other factors can all make wifi connections unreliable. Another option is to use powerline networking (also called homeplug) adapters -- which plug into any old electrical outlet.
Stick with name brands when it comes to powerline networking: D-Link's DHP 303 and 301 are both good choices, and Netgear offers a bevvy of different options -- including plugs which allow you to connect more than one device per plug.
A good wireless bridge or powerline networking kit is a great way to avoid unsightly cabling.