This takes a keen eye but in several places there will be a magazine on the ground with no special actions. Check it in order to get the porn fairy who will say something then leave with a parting gift such as a rare item or multiple secret tokens. The fairy is also found outside of Larry's window after the game is completed and will sell you tapes so you can see the two endings you missed.

The vibrantly-mohawked Nigel is located in several places throughout the game and he can sell you call kinds of unlockable items (art, strip games, etc). Post-makeover-Russell can do the same for you as well, though, later on in the game.

As you know Larry can shoot pictures of anythnig he wants, but the zoom is only 5x. There is a 10X camera hidden in one of the Swingles camera at the beginning, just knock it over and claim it.

In the Greek quad, there is a cheering squad. Take pictures of them then sell it to the college guy talking to a girl near the sorority house. It's about as easy as other camera side jobs, but this can be done repeatedly without the gradual loss of profit.