After hours of researching I concluded that there was a gap in the products offered for policing home networks. Nearly every viable solution I came across was designed for business networks and were invariably too expensive and too complicated for a simple home network. My client was trying to restrict his teenage son's internet usage not manage twenty employees. I also strongly considered OpenDNS, but its home service didn't allow for time usage restraints and the sort of features one would expect from a conventional web filtering program like K9 Web Protection.
I eventually arrived at three separate solutions. The first solution was Bsecure's Family Safety for Windows. It was the only software solution specifically for home use that could be configured like Net Nanny but applied at the router level. The implementation is similar to OpenDNS in that the user changes the DNS settings on the router to connect to the DNS servers managed by BSecure. The cost for this service is $49.95 per year.
The next two solutions I found were hardware solutions. Hardware solutions provide some advantages over software solutions in that they are more difficult to circumvent. The first was the IBoss Home Parental Control Router. The router is a relatively cheap $50 wireless-N router, but you must pay $60 for a yearly subscription to use the router, which gives you the ability to filter content. Reviews of the router were decent to good. The router appears to be an average wireless-N router, but the web filtering and time management options were impressive.
The last solution I found was the Zywall USG 20W Unified Security Gateway. It can connect to Blue Coat (same subscription service that K9 Web Protection uses) and Commtouch to filter web content. The router also offers a whitelist only option, which completely restricts internet access except for the sites you add to the whitelist. The cost for this router was at least $210 and that's not counting the cost of the subscription to Blue Coat and Commtouch.
My client selected the BSecure software solution because it's both the cheapest and probably easiest to manage without having to change many router settings. I'm scheduled for a service call to install BSecure with my client and will post again to say how it went.
Please post your comments if you have any experience with this issue.