Several people have asked about the similarities and differences between grocery stores in the U.S. and Australia (I guess they figure since 'you are what you eat' you can learn something about a culture by its grocery stores). I'll try to list some notable differences:
Satay sauce (spicy Thai peanut sauce) is as popular as ketchup (which Aussies call 'sauce' and charge 10-20 cents a pack in fast food places for). It is routinely found (multiple brands) in grocery stores, and many restaurants, regardless of their type, offer some satay-based meal. We actually had a chicken satay pizza at Pizza Hut a couple months ago!
Another big item is sausages. One is much more likely to find sausages at a barbeque than hamburgs or hot dogs. 'Sausage sizzles' (outdoor grilling of sausages) are very common, with many events (sales, concerts, meetings, student gatherings) including them for free or cheap. Sausages are made out of just about anything, and come with various flavorings cooked into them (including the above-mentioned satay). They are also very cheap to buy at the grocery store.
The brik-paks used for juice boxes in the U.S. are very popular here. The 1 litre sizes for milk and juices cost the same price as the chilled stuff in bottles (and keeps for a year or more), with no noticeable difference in taste. Very convenient. Wine comes in these things, too (called Chateau Cardboard by the locals), in 2 and 4 litre sizes with a nice little tap to keep it well sealed. Inside is a sack which collapses to keep air out. Very popular at barbeques, but sort of mediocre in quality.
In general, folks are not very cholesterol-aware, nor do people generally cater to vegetarians very much. Meredyth has suffered with airline food, since the choices tend to be all with beef or lamb. The vegetarian options are rarely more than a salad with a roll.