Very nice start, I had to do buttons for my last web app and ended up using less nicer tool. I suggest to add next two features which can be essential for some

Very nice start, I had to do buttons for my last web app and ended up using less nicer tool. I suggest to add next two features which can be essential for some scenarios: 1) Add way to choose background color (i.e. page color) for the formats that don't support transparency (gif and jpeg). PNG gradient transparency is not supported in IE6 and quite often there is a need to render button edges with background color preset because of that. 2) Pre-render images for other button states: hoovered and pressed. And afterthought: consider supporting iPhone-style buttons (i.e. like big red "delete contact" button and small blue buttons), I'm sure a lot of people are looking for them.