WiFi Booster

This might be a inexpensive solution for someone who has an existing but weak signal:

http://www.l-com.com/content/article.aspx?type=L&id=10174&cmp=102312Wire...

This will not demodulate the signal from the cell phone carrier. It will only amplify an existing wi-fi signal. Click on the links at the bottom of the page for more options. An outside antenna would of course be more effective.