David Dantowitz's new Apache-Apple Event Bridge (AAEB) will be a very handy tool for Mac-based home automation. It allows you to easily execute local (on the web server) AppleScripts from a web browser. In the demo video, you can use this to grab a screen capture of the server. Other uses off the top of my head would be to make announcements, trigger home automation actions, or just about anything else you can cause to happen using AppleScript.

You'll want to consider security, but for a measily $10 this is an easy decision to add to your system.