Yep do what Sunny said.
You are eligible for a CSE account (which means you get an email @cse.unsw.edu.au and computer access) if you are enrolled in a CSE degree or in a CSE class.
If you're just doing a CSE class you only get the account for the time of the class, otherwise it's there as long as you are
PS. New ppl read the Yellow Form rules and don't break em! If you eat or drink (or CSE staff can even _see_ your drink bottle or food) then you will get a warning. 3 more warnings and then it's $50. Save yourselves the hassle
PPS. Any questions about CSE facilities, computers, wireless access, stuff like that.. email the CSE Helpdesk, they are there to answer any Qs...
helpdesk@cse.unsw.edu.au
Or check out
http://www.cse.unsw.edu.au/~helpdesk/ at the Help & Resources section it links to some FAQs.