What about this software?
http://www.farstone.com/home/ensite/products/dit.shtml
quote:
Originally posted by http://www.farstone.com/home/ensite/products/dit.shtml
DefendIT 1.0 is a Wi-Fi router security setup and monitoring tool, which was designed with the non-technical user in mind. When you purchased your Wi-Fi router, you had to navigate through a complicated set of instructions to properly configure multiple security settings and in some cases, your Wi-Fi network may still be vulnerable to unwanted visitors. Perhaps your neighbors are using your Wi-Fi signal to access your PC or your Internet connection and you may not even know it!
By the way, its not free...