1) I've never seen a coupon here. Those that know me well know that I love watching "Extreme Couponing" on TLC and get a disproportionate thrill from using a .50 cent coupon. It's like a game to me, so it's quite sad that coupons appear to be few and far between, with the exception of a few Groupon deals. Maybe I'm just looking in the wrong places, though, and I would love to stand corrected on this observation.
2) This city is SO quiet. For its size (4 million plus), I can't believe how quiet the streets, public transport, etc. are. I've realized a big reason for this is that, unlike in large American cities, people don't honk obsessively. In fact, I think I've heard only a handful of car horns since we've been here. In the same vein, police sirens are few and far between. Melbourne is extremely safe compared to similarly sized cities in America (LA or Chicago). This is reaffirmed in the lack of sirens. Again, I could count on one hand the number of sirens I have heard in the last two months.
3) Tipping is not expected anywhere. Although things are really expensive compared to what we're used to, it does help when you don't have to tack 10-20% onto a service every time. However, this affects the level of service you receive, at least at most restaurants. I'm used to the server constantly topping off my water glass every five seconds, which actually kind of makes me nervous and I feel like I have to drink it super-fast. But that could just be me. On the contrary, the servers here fill up your (small, ice-less) glass once and you pretty much have to stand on the table to flag someone down to refill it. A happy medium would be ideal.
Those are the three that stick out to me right now, and I'll continue these "observation" posts as I encounter more differences/oddities/Australianisms.