As of this episode, Barney had slept with 282 women.
During the absinthe cut scene, Marshall says they have water, soda, or purple stuff. This is a reference to an old Sunny Delight commercial.
The music heard in the background of the bar when Marshall almost gets in a fight with his mirror self under the influence of Gin is the same music from Okay, the club in S1E05 "Okay Awesome"
The music during the floating scenes is Gymnopédie No. 1 by Erik Satie
The song heard at the end of the episode, when Lily and Robin are claiming their booth back, is an guitar version of Summer Love by Justin Timberlake.