To be "with the group" or to "be cool" as determined by your peers. The "trolley" would be something one would want to be on.
One may also want to make it a point of saying that someone is not on the trolley, instead of just saying that they should get on it. This implies that the person is so uncool that they cannot even try and be cool.
Another popular use is pointing out that a particular member of your friends circle is on the trolley in an attempt to rub it in the face of the person who isn't.
This phrase is usually used in a ribbing manner towards friends.
(After making a faux pas, doing something the group would consider uncool, etc) Come on Jason, get on the trolley.
similar to "got off my kool aid," but with way more Italian jealousy. When an absolutely gorgeous redhead is involved, an Italian guy would say "get off my red trolley!"
1. Select a player (real or fantasy) during a sports draft to spite or anger one or more of your opponents because they had intended to select him/her.
2. Select a player (real or fantasy) during a sport draft to put one or more of your opponents at a strategic disadvantage.
1. Billy hate drafted Chad OchoCinco because he knew Sam had wanted him since he is from Cincinnati. Billy already had plenty of players to fill that position but wanted to make sure Sam didn't get him.
2. Billy hate drafted Peyton Manning because he was the only good quarterback left and he knew Sam had been planning on drafting him.