partial residuals in plot.gam()

All,

Sorry for bombarding you with GAM related questions, but...

I know a partial residual option in plot.gam() is on Simon Wood's todo 
list, but since I'm in the midst of a project and not yet having acquired 
sufficient R knowledge to code something usable myself I'll have to put my 
trust in you. Anybody got some code lying around for doing this? Or if 
someone can supply me with enough hints for doing it myself, I'd be most 
grateful.

Thanks,
Henric