I think that's a good one! - Although I don't even know my Glitche's birthday (is there a way to find out?). I guess party recipes and decor would be a plus for out parties!
A fellow glitcher had her birthday on the last day of the last test and we felt there really should be a way to mark one's birthday here, if they wish. Maybe attach a balloon to said glitcher so that everyone they pass by knows it's their special day? Although it would be difficult to determine what's the Glitch equivalent of a RL date.
Maybe a disco-lights powder?
BTW, I saw one of the devs was exploring an indoors party venue (or something like that)... :)