I often use this Logic plug-in called "Match EQ", which lets you analyse 2 files and apply the EQ curve of the first one to the second. I use it pretty much only to quickly extract the information I need when I'm comparing material and it's become an invaluable tool.
 

 
As it turns out, after using it to show something to a pal, I turned him on to that thing, but he is working on PC. I know Steinberg used to sell something similar back in the days (FreeFilter it was called, IIRC), but I'm sure that there are other similar PC options out there, right?

http://www.meldaproductio....php?id=MAutoEqualizer
http://www.meldaproduction.com/plugins/product.php?id=MAutoDynamicEq

Freefilter was awesome. I think har-bal does something similar too. The melda product works even better than match eq imho

Wow, that was quick. Thanks guys!

BTW, MeldaProduction puts their plug-ins on sale regularly for as much as 50% off.

I've not used it personally, but AFAIK you can do this with Ozone too.

I use Ozone 5 for that.

There's also Waves Q-Clone.
 
[There's an old 32 bit version of tc electronics 'Assimilator' as well, but apparently there are some issues with it - which is rare for them.] 

Voxengo CurveEq also fits the bill. It's included with Cubase as well
http://www.voxengo.com/product/curveeq/

Awesome - thanks for all the suggestions guys. :)