See the article below, but it looks like Untangle has already outsmarted my Sonicwall. While it's not blocking everything, the free content filter download (installed automatically with a single click on the client console, by the way) has already blocked a few proxies, the major social networking sites, and a wide variety of porn. At the same time, it has logged the internal IP address of the user attempting to access the blocked content. More updates to come, but for something free and set up in an hour, I'm mighty impressed.
The screen resolution issue is addressed by simply accessing the gateway remotely through any Java-enabled browser, allowing the machine to sit headless quite easily. Sweet!