I'm thinking of cutting the signup off on friday.  That would give me the weekend to get roles squared away and get pm's sent out.  I'm stoked to see so many people in the game.  I think it's going to be a lot of fun (ie: zombie blood bath).  Then we'll be all set to start monday.  I'm thinking the first three days will be 48 hours, then go to 24 hours after that.  As always, I'm open to thoughts and suggestions on this.