To promote our impending launch, I think it would be cool to have a launch party. Some elements that it could include:
Live text chat
Live audio
A call-in show format, using BlogTalkRadio.
People identifying favorite site content to date.
A ribbon-cutting in which we count down to a SE staff person throwing the switch to launch the new design, and we all reload and see the new site at once.
Divrei Torah
A panel discussion, featuring notable people from within and/or outside the site, on some relevant topic, such as "the role of online communities in discussion of Halachic topics."
A synchronized "Lechaim," with each participant using their own beverage of choice, perhaps with some dignitary delivering words of blessing. (Inspired by food-oriented comments from Double AA, Shmuel Brin, Dave, and Gershon Gold.)
What do you think of this idea? What aspects would you like to see or not see? Any other ideas?