Setup a sniffing attack on your machine.
You can do this in many different ways. My recommendation is:
Setup your linux machine for telnet.
Setup Dsniff on your windows box
Run Dsniff and telnet from windows to your linux box.
See what you can capture. You may need to use a hub (there are some evolo hubs laying around I think).
Second Part -- Use ettercap to detect a connection on your machine and also see if you can use the -C switch to sniff usernames and passwords. Setup the connection and see what you can learn. Report in on the use of ettercap.
Third Part -- Compare ettercap and dsniff in a whitepaper (usability, etc.).