When Should I Rack?

[vlbaby]

Just a quick question to all the beer brains out there. I'm a bit confused about the timing of racking the secondary. I've read people say that you should rack just before the ferment has completley finished and has almost slowed to a stop. And I have read that you should fully ferment in the primary first before racking. Which is better, or does its make any difference?

 

[nonicman]

Just reading John Palmers piece on this (from a link Wreak posted)

using secondary fermenters