If you were to create an inital button using sodipodi and save it as a
svg file ( the default I think) then you could use a simple sed script
to create icons by replacing the demo text with the text required for
that button.
Doesn't that leave me with the problem of long text not fitting on short
buttons?
In image magic there is an option to create a "label" which makes the image
as big as the work on your label. You can then superimpose the corners
using gravity to position them.
I haven't kept up with this thread at all but there seems to be an issue