First time that Barney accepts a challenge without actually being challenged by anyone.
Marshall says his professor is in her late 40s. Jane Seymour was 55 when this episode aired
The popular internet meme "That's a penis" originates in a clip of this episode, as Hammond unveils his architectural design to the investors.
This episode features a stolen baseball signed three times by Pete Rose. On April 20th, 1990, Rose pleaded guilty to two charges of filing false income tax returns not showing income he received from selling autographs and memorabilia.
In the previous episode, Marshall is invited to go to a wedding with another male. Robin and Ted joke about them being Wedding Crashers. Jane Seymour played the mom in the movie Wedding Crashers and guest stars in this episode as Marshall's professor.