#1. A Xbox webserver app that allows you to set a "index.html" file, so that when a user types in your Xbox's IP in thier URL bar, they get that page. Of course it would need to be fully functional (ex: links work, ect).
#2. Wine or WineX on Xbox. I'm not really sure how this could be accomplished. It might be done by making a Linux distro that just boots Wine without any other gui. Or it could be done by making an Xbox app that allows you to select an exe file then it attempts to run it.
I'll pay $200 (paypal) to whoever develops either one of those. I got $400 to blow, and I feel that these apps could really contribute to the scene.
For example #1, someone could open a professional webhost buisness using modded Xbox's! #2 would just be downright awesome, especially if it works well.