I guess I'll be first then! I am Canadian but my employer was kind enough to send me on a business trip to Sydney in Nov./Dec. of 1996. I've been a fan since the first album and my wife and I saw them here in Canada in 1994. I knew that they were splitting up, but I didn't know about the Opera House concert until the flight attendant passed out copies of the Sydney Morning Herald on the Honolulu-Sydney flight. The concert was supposed to have taken place the day I arrived; I would have been an absolute zombie had it gone ahead as I don't sleep well on airplanes. Fortunately, there was that delay until Sunday which worked out well for me and allowed me to get some sleep.
I was only able to get to the Opera House later in the afternoon when the concert had already started (i.e. the opening bands). They had closed off the area immediately around the Opera House, but I waited around and fortunately for me, they let more people in (me included). I latched on to another group and we made our way through the crowd until it was impossible to go any further. I was, you might say, far stage-left (i.e. if you were Neil Finn facing out toward the crowd and Opera House, I would have been standing far to the left). I could see the front of the stage, but not the back.
The thing I remember most, after the awesomeness of the concert, was the density of the crowd. Simply moving my hands from waist-level to face-level, or above my head, to cheer was a real contortion, it was so packed. I am reasonably tall, but I wouldn't have wanted to be a short claustophobic person.
The concert I had seen in Canada was without Paul, so I was thrilled to see them all back together again (with Tim too!). I knew I wasn't in Canada due to the obvious song recognition of the crowd, and the singing along (DDIO obviously, but the crowd was in good voice for lots of other songs too).
I remember some guy actually climbing up the roof of the Opera House. I think people were wondering if he was going to fall (he didn't). I also remember some guy being launched into the air by others in the crowd, near the front. It looked pretty crazy in the centre near the stage. I have to say though that despite the density of the crowd, it always felt safe and friendly.
I've had to use the Internet in the years since to actually get the playlist of the concert as I don't remember all the songs; just that it seemed to be all my favourites. The next year, MuchMusic (our equivalent to MTV here in Canada) played an abbreviated version of the concert which was nice. I'm dying for that DVD to come out...hopefully soon!
Hopefully a few Sydney-siders who were there will also post their memories here.