ok, well I find the differences in the football codes (gridiron, soccer, Aussie rules, rugby etc) fascinating. They all developed from a common ancestor.
Anyway, Australian Rules football is played on a large oval field, usually about 150 meters long. There is no offside, and play only stops when the ball goes out of bounds or a player takes a 'mark' (catches the ball after it has been kicked more than 15 meters). The ball can be carried forward, kicked or 'handballed' (an odd sort of pass. Basically you hold the ball in one hand and punch it with the other) in any direction. The aim is to kick the ball through goal posts at either end of the field.
The game is very fast moving, with some teams favouring a long-kicking style (not dissimilar to a long-passing game) and others a fast-passing, more run-dependent style.
The similarities with gridiron are what we call 'shepherding' and you call 'blocking'; the ball carrier is aided by teammates who run in front bumping opponents out of the way. There are also a lot of spectacular catches, as guys run at full speed to catch the ball and often get absolutely axed after taking the catch.
One thing I think gridiron could do (apart from removing the hard-shelled equipment) is allow players to climb on each other to take catches and block kicks. It's allowed in rugby and aussie rules and it can be really spectacular. http://www.youtube.com/watch?v=pZ0W9SbBHqo
The game doesn't feature too many smashing RB style runs, as getting caught with the ball results in a turnover, but when a guy takes the risk and tries to run over opponents it's always a crowd favourite.
Anyway, the pros of Aussie rules are the sheer speed of the game, the spectacular kicks and catches, and the ability for a team to pile on a lot of points very quickly.
Cons? Well, because there are no offsides there aren't usually the big tackles you see in sports like rugby or gridiron. for the novice, the game looks like absolute chaos, with people often calling the game 'Australian No-Rules Football'.
Anyway, fans of field sports should check it out. You do occasionally see former Aussie footballers changing codes to play NFL (always as punters). Sav Rocca for the Eagles and Ben Graham for the Cards are both former AFL players.