http://www.househacker.com/ househacker/tags/wifi
The antennas supplied with your router are designed to be omni-directional, meaning they broadcast in all directions around the router. If your router is near an outside wall, half of the wireless signals will be sent outside your home, and much of your router's power will be wasted. Most routers don't allow you to increase the power output, but you can make better use of the power. Upgrade to a hi-gain antenna that focuses the wireless signals only one direction. You can aim the signal in the direction you need it most.

and also changing the router's wireless channel:

Wireless routers can broadcast on several different channels, similar to the way radio stations use different channels. In the United States and Canada, these channels are 1, 6, and 11. Just like you'll sometimes hear interference on one radio station while another is perfectly clear, sometimes one wireless channel is clearer than others. Try changing your wireless router's channel through your router's configuration page to see if your signal strength improves. You don't need to change your computer's configuration, because it'll automatically detect the new channel.

Check out the rest of the tips to ensure your wireless network is running at it's optimum level.

Link: 10 tips for improving your wireless network.]]> http://www.househacker.com/permanent/Microsoft-Offers-Ten-Tips-on-Improving-your-Wireless-Network Avega Systems are developing WiFi speakers that connect to your wireless home network. The speakers, called "Oysters", play digital audio streamed directly from your computer. Listeners can control, browse and select media from their PC through the Oyster's graphical remote control. The speakers will also accept input from a CD/DVD source and wirelessly distribute the audio to the other speakers in the room. The Oysters also will accept iPods or other MP3 players, via USB port, which will, again, trigger the connected speaker to distribute the audio via WiFi.

The speakers feature wireless connectivity (801.11 a/b/g), support for DTS, 5.1 surround as well as MP3, OGG, WMA, AAC and FLAC digital audio formats.

The unit also has 2 S/PDIF optical connectors and USB port for wired connections.

CNET feature on the Oysters with video.
Company FAQ and spec sheet (Both PDFs)]]> http://www.househacker.com/permanent/Avega-Oyster-WiFi-Speakers
Use one of the included extension units to connect your router to the AuraGrid, and wire the additional extensions into the cable entry point of the rooms to be connected. Each comes with an antenna: Rooms that are equipped with an AuraGrid antenna will enjoy maximum wireless signal strength as well as data throughput without interrupting cable TV/Internet services.

Great idea.

via engadget]]> http://www.househacker.com/permanent/Use-Existing-Cabling-to-Extend-your-Home-WiFi-Network-with-AuraGrid