Here's a reference to Bill's Blog on the subject, just for more cannon fodder.
http://frcdirector.blogspot.com/2009...-regional.html
What I've heard for the DC regional is that they want everyone to put their parts in a separate box to be weighed, and that they will check and weigh
everyone's allowance. The details may change though, and the squeemish part is that we'll have to wait until next Thursday to see for sure.