In the scene where Shawn wakes up Gus, Gus has a picture of his younger self on his night stand. Shawn is wearing the exact same clothes as Gus in the picture, and even matches the pose exactly when he wakes Gus.
Pineapple reference: pineapple smoothie.
At around 20:50 into the episode, Gus reveals that as a kid, he was infatuated with his 37 year old babysitter. The song playing on the radio in the background is Stacy's Mom by the band Fountains of Wayne, which is about a young boys infatuation with an older woman. This parallels the conversation that Shawn and Gus are having at that exact moment.
2400 motel is used a lot in shows filmed in Canada, such as "Supernatural".
In the beginning of the episode young Henry and Shawn are on a stakeout to discover who is stealing their newspaper. When they catch the neighbor Henry grabs him and orders him to hand the newspaper to young 1980's Shawn. The paper is a USA paper from 2006 with articles related to The Katrina hurricane and calling out George Clooney as a hypocrite for protesting the Bush wars but asking him to send troops into Darfur.