During the flashback in the car ride to Ted and Stella's wedding Barney is doing the dance to Beyonce's "Single Ladies" in the back seat.
At 11:00, Lily admits to making a sex tape, and Barney runs out of the pub. He runs passed a very tall patron. That tall patron turns his head towards the booth, revealing that he is Conan O'Brian.
When the camera cuts to Ted and Robin's apartment after Barney finds the sex tape, onscreen reads "46 minutes later", which is exactly how much time it takes to get from Marshall and Lily's place in Long Island to Ted and Robin's place. We found this out in Episode 14, called "46 Minutes".
"When a door closes...well, you know the rest" is derived from "When God closes a door, He opens a window"