I use this game on a few MSN sites and it has taken off good!  Basically you start with two actors or actresses who appeared in a movie together...the next person takes the last named actor and finds another movie they were in and names a co-star and so on.  For example:
 Richard Gere and Julia Roberts
 -"Pretty Woman"
 Julia Roberts and Denzel Washington
 -"Pelican Brief"
 and so on!
  
 I'll start....
 Joseph Fiennes and Gwyneth Paltrow
 - " Shakespeare in love"
  
 Gwyneth Paltrow and......