Have you tried Yahoo's fortune cookie site?  
Crack a cookie and have the site that'll be 
updated next written inside ^^
Anyway...
I meant, if the company would contact ahead of 
time and say that they are starting the update 
and should be done in APPROXIMATELY 'XX' amount 
of hours/minutes.  
This would work especially well for pages like 
mangaya or hobby shop k, etc. that update less 
than the more common ones such as anime-taro.  
That way everyone could all be there for the 
update around the same time.  I guess it all 
depends on how much you like sitting around your 
computer for hours on end waiting for something 
that you don't know when/if it will come (nooo... 
i'm not talking from numerous experiences -_-).  
No thanks for the sour reply, I give you a big :P
      __
(O   |__)
   ^ |
(O   |

j/k ^^
-Eric