Networked Computers

Just a quick question, when I go to my school we have a Wired and Wireless network. I am usually connected to the Wireless network, when I go to my "Network" page in OS X it shows all the schools computers (e.g: R219X1, R219X2, R220X1, R220X2 etc) Basically it displays the computers in each room and the number of the computer. This is great because I can log in with my school ID and connected to my private drives / print etc.

However in the Network list are also other students, from other Macbook's to iPads, Playbooks etc. Basically anybody connected to the internet. I would like to know how I disable other people from viewing my Macbook in that "connected list" or even making it so I don't show up.

I have all my OS X settings to not share anything, but I have never actually used somebody else's computer to see if they can connect to me or even see me. Any help would be great!