I second the ernst stocket organizers. they have 2 different styles where you pull them straight off or have to give them a quarter turn to unlock them. They're basically the same as the metal rails but a little better quality. the kind with the plastic fingers with the size marked on them are fine if your socket collections matches up perfectly with the organizer, but if it doesn't then you either have blank spaces or sockets on the wrong sized peg.

go here and search the forum for "organizers" and you can spend weeks reading about tool organization options and looking at pictures of other peoples toolboxes: http://www.garagejournal.com/forum/forumdisplay.php?f=4