RE: Filtering network content based on User Subscription

Your best bet in this case is to place a appropriately sized firewall at the customer's site, i.e. Cisco PIX 501 - 515 series or SonicWall's equivalent and link it to a WebSense or N2H2 content filtering server at your NOC. [snip] Scott C. McGrath

Joe, Cisco's Content Engine can also do the functions that Scott mentioned, plus gives you the benefit of web caching. It's very feature-rich, and the command line looks a lot like IOS. You can configure it to FTP your whitelist of URLs, and set up user-specific or global time restrictions, which address a couple of your specs. For the latter, I think you need the Smart Filter module, which is not part of the basic Content Engine distribution.