I got a new gadget the other day. It was a powerline network adapter kit. It looks like this:
Comes with these two adapters and 2-6' ethernet cables. These adapters turn the wiring in your house into a very efficient network without having to run any additional wires. You plug one into a power outlet near your router and then plug the ethernet cable into the adapter and the other end into the router. Take the other one basically anywhere in your house, plug it into a power outlet. Then plug the ethernet cable into the adapter and the computer equipment that you want to network, and you are done.
I used this to replace an external wireless adapter that I had on the PC that collects the data for my weather station. I'm using a older desktop so it didn't have a wireless card. This actually works better because wireless speed, unless you have one of the new "n-type" routers is pretty much limited to 57mbps. When you use a wired connection you get the full benefit of 100mbps. These adapters are rated up to 200mbps so they work just fine.
The only issue I saw was that they don't work if you plug them into a surge suppressor. These are definitely worth taking a look at if you don't have a wireless card or maybe the signal is weak in specific areas. I ordered mine from eBay but you can even find these on the Wal-mart site. Shop around to get the best price. I paid $39 with free shipping.