cross-browser solution
/* * First create a file filters.svg with the following contents */ img {
filter: url("filters.svg#grayscale");
/* Firefox 3.5+ */ filter: gray;
/* IE5+ */ -webkit-filter: grayscale(1);
/* Webkit Nightlies & Chrome Canary */
}
img:hover {
filter: none;
-webkit-filter: grayscale(0);
}