Well I've started making Icons from HOL images and it literally takes seconds to do each set.
Drag (or use a shell command for lots of pics) the PNG pic over to image2icon and jobs a good 'un. Then dumped into the lettered drawers. As I mentioned above, this will be an ongoing project as and when I have time.
They're obviously not as good as frogs, but they'll still make a good addition to the classic WB icon drawer for all you WHDload freaks using standard WB3.