I saw quite a few, aside from the obvious Oceanic poster and Lost poster on the side of a bus.
- Main character wakes up in a place that he does not expect to be (like Jack in the pilot episode)
- An animal in a place that you don't expect them to be (a kangaroo, like the polar bear)
- A bird flying into a window (WAAAAAAALT!)
- Focusing on eyes (before seeing Mark's flash forward, and at the start of many Lost episodes)
- The numbers (Mark's address - 1684 = 16, 8, 4)
Did anyone notice any more? I couldn't stop giggling as I watched!