Peer to Peer at School.

Well it depends really on what they are using to catch you. In my department we use a packet analysis system that simply looks at traffic patterns and shuts down suspicious ones. This has proven effective even against encrypted traffic because the pattern remains the same. If, however, your school's IT department is only blocking by protocol or port number you might be in luck. Try changing your bit torrent port in transmission to a random number. I am not familiar with Transmission ( i use uTorrent on windows), but try enabling the encryption feature and see if that gets you any where. Regardless of what you do though all traffic is traceable back to your macbook because everything that comes in and goes out of your computer contains its hardware id (MAC address). So in the end even if you can make transmission work, they can still trace what you've been doing back to you. The only real way to keep it from being traced back to you is use an anonymous VPN connection that routes through a country where laws do not require them to keep DHCP records. These types of VPNs are referred to as darknets.