>So. What do you do when games turn silly? And should I just ride with it 
>and keep it silly even as they try to save the world?

A former DM introduced the idea of the elemental plane of silliness. Pop the 
whole party into an alternate plane, let all the silliness run its course in 
as over-the-top a manner as required, then return them to the serious 
setting when they're ready to continue. I thought it worked pretty well.

----------------------------------------------------------------
GMAST Home Page:  http://www.phoenyx.net/gmast/