transparent icons in toolbar?

[Mark Burgess]

I have a couple of applescripts I like to keep in the OO toolbar, but
I can't for the life of me figure out how to apply custom icons that
are transparent. I can copy the toolbar's gradient background and put
it behind the icon, but this only gives the illusion of transparency
when the document is active. When it's inactive I can see the icon's
background.

I've searched high and low for instructions for creating custom
transparent icons for OS X but it's surprisingly hard to learn how to
(a) how to create them, and (b) how to apply them to a file. I can
copy/paste the OS9 way (through the get info window) but no matter
what I try I lose the transparency.

I know it's possible because kGTD does it...

Thanks,

--
Mark