e1n:

If you’re a Photoshop user and you hate how PS switches your active layer when you undo, causing you to paint/draw on the wrong layer and not realize it until way later, then this is early Christmas for you.

(and I’m sure there are a whole lot of you)

http://draugdesign.com/2011/stepbackwardsmart

Thank you Will Fuller for writing this lifesaving script, Anders Christensen for hosting it and making it available, and Sherwin Abesamis for finding this link.