O-Week was awesome! And from what I gather, much the same as any other uni's. During the day theres stuff on to help you work out where things are around the uni (tours, meetings with other ppl. from your course, getting your enrolment sorted, self defence, the occasional waterfight and bbq) and at night time theres all different stuff on depending on the theme of O-Week for that year.
Activities vary but last year we had a trivia night (not your normal sorta trivia night though), a love match game thing (it was valentines day), um...a pool party, karaoke, and heaps of other stuff. I can't even remember it all but it was heaps of fun
Around 11 or 12 each night the buses turned up to take people into town too for those still up for partying...