Grayscaled images through CSS in Firefox?

[squeezypie]

I know the CSS tag for making all the images on a page grayscaled (that only works in IE). Now, I know I've seen this tag used in Firefox sucsessfully at least once, and I really want to get my hands on it again. Could anyone help me out?

[Joe[y]+]

if it was in firefox then i'm certain it was more likely javascript... unless there is a way i haven't heard. give google a hit with it.