When Frasier loses the award for Best Call-in Host, Martin tells him, "Sorry, Son, you can't beat a dead guy." which is in fact just what David Hyde Pierce did at the 1998 Emmy Awards when he won the award for Outstanding Supporting Actor in a Comedy Series over the recently murdered Phil Hartman.
Niles says that he's going to hear Tony Bennett sing at Frank Gehry's birthday party. Gehry is a Canadian-born American architect and designer who, among other building, designed The Museum of Pop Culture or MoPOP. It is a nonprofit museum in Seattle, Washington, dedicated to contemporary popular culture. It was established in 2000, which was three years before this aired. MoPOP is located on the campus of Seattle Center, adjacent to the Space Needle and the Seattle Center Monorail, which runs through the building.
This is the second time Frasier sees Roz's sister, but she seems to have forgotten everything which happened the first time in the episode "The Guilt Trippers". Up to this point she should know him only as Roz's boyfriend Roger.
The title it a reference to "hee-bee jeebies".