For those of you that don't know, this feature is available in cs2 and cs. And I think they had it (though fairly primitive compared to the cs3 version) in 7 as well. But the blending in cs3 is actually really smart and works very well. I have used this more than once on stuff, I think it's an awesome underrated feautre.
Yea i tried it in CS2 it kinda sucks, but its possible. I seen a video on the CS3 version and its an itelligent piece of plugin. Ill definately make some use out of it when i get my copy .