If you don't want to go through all of the syntax on Apple's Dev page... just try some simple searches based on common file attributes listed in the 'More Info' pane of Finder or just about any App.

here are a couple of examples I found...

'kind:image gray'
(returned a bunch of black and white photo's I had scanned (the colour space was listed as 'Gray')

'kind:image rgb'
(returned my colour pictures)

'kind:music 192'
(returned any mp3's I had encoded at 192 bit rate)

'kind:image 180'
(returned any image that was 180 pixels in width or height OR was 180 DPI)

'kind:music 2004'
(returned any music file that had the year of release listed as 2004)

'kind:music classical'
(returned any music listed as classical in the ID3 tag)

A nice easy way to get your files organised.

Hum I'm tired but I'm still search conditionnal search in spotlight for example searching all my illustrator AND esp files modified last week ? only possible through Automator ?