We found some guy's laptop that had some shared folders. There were some images from a digital camera in there. We opened one up and it showed what looked like a new kind of reflection-based video projection technology. There was a focused light source on the floor aimed at an angled glass panel that apparenly had reflection-adjusting pixels on it because the reflection on the wall behind the light source was a frame of a movie. We probably stumbled on some secret new technology this hotel guest was on a business trip to present to some suits.
We also determined what kind of switch the hotel uses. We were able to telnet to it but couldn't log in, and when we looked up the device's documentation online it looked like it doesn't ship with a default password (unlike things like cable/DSL routers that usually use admin:(blank) as the default login). Oh well.
None of this was my idea, of course. :)