In the scene when Ted is doing roll call in his class, he calls out the name Jamie Adamic. Jamie Adamic is the name of one of the assistants to the producers on the show.
Nick Swisher is the husband of JoAnna Garcia-Swisher who plays Maggie Wilks in the Season 5 episode, "The Window".
When Ted and Barney are checking the "scouting report" for Barney's next conquest, the main theme from "Major League" can be heard playing in the background.
When sitting at the table with Swisher Robin asks if Mookie Wilson is a thing. Mookie Wilson was a baseball player in the 80's and was a member of the 1986 World Series Champion Mets. Wilson was actually the batter when Bill Buckner committed his famous fielding error in game 6.
When Barney exits the bar with the 4th woman, he is touching the wall (where there might be a poster or a sign hanging) with 4 of his fingers. This could be another of many sports references in this episode, as the Liverpool FC legendary soccer player, Steven Gerrard, was known for touching the iconic "This is Anfield" sign with 4 fingers on his way to the pitch before every match.