Nikon D5100 stolen/lost?

In my school, I'm enrolled in a Photo Imaging course and I'm allowed to bring my camera, the Nikon D5100, to that class. I have done it several times before, and made it a habit to check that I had my camera on me throughout the day. On Thursday, I was in a different class after Photo Imaging, and I was talking to a classmate, got sidetracked, and realized I didn't have my camera on me after the class ended. I went to that class at the end of the day only to have the teacher tell me he didn't get up during his lunch period, so he wouldn't have noticed my camera bag. He had a class after his lunch period, so someone in that class HAD to have taken it (this was right before the end of the day).So I went to security and looked through surveillance tape, but the security guard was not very helpful and got frustrated easily when I told him EXACTLY the five minute period in between classes that you could see the thief walking out with it. He insisted on zooming in on only a certain hallway, which happened to be incorrect; how ignorant! I'm going back to the security office on Monday to see a different security guard to look through the surveillance tape with. LOTS of people in my school can identify my camera and camera bag, so the news is all over Facebook, Twitter, etc. I need my camera- the newspaper and yearbook clubs frequently use my pictures to fill their publications with, and whoever stole the camera is serving a huge injustice to not only me, but to everyone that is able to utilize my pictures. Any other suggestions?

Added (1). I'm not a "klutz." I have never lost expensive electronics, and this is the first time that something like that has happened to me.

Dig up the serial number and report it as stolen

There's little else you can do to be honest. You can advertise that it has been stolen but unless the thief is that rare kind, an honest one, then all you can do is hope the security come up trumps.

Too late now, but there's a service that costs about $10 per camera to register it so that if it is ever pawned, sent in for repair or sold, there's a record of the owner that can be checked rather easily.

Link:

http://www.gadgettrak.com/

What to do now?

* tell your school of the theft and the serial number of the camera
* report the theft to your local police department

The rest you seem to have covered quite well (Twitter, Facebook, etc.)