airbrushtutor
Love Spreading Overseer
No doubt some of you already know this one - it's not the be all and end all to paint mixing but it's great for adjusting colors on the fly 
[video=youtube;D2UJ7ID_zWY]http://www.youtube.com/watch?v=D2UJ7ID_zWY[/video]
[video=youtube;D2UJ7ID_zWY]http://www.youtube.com/watch?v=D2UJ7ID_zWY[/video]