[Plugin: Edit Author Slug] Automatically create firstname-lastname slug?

Hi, I can go to user profiles and change author slugs manually to match the firstname-lastname convention, however, is there a way to do this automatically? I.e., every time a new user registers this plugin would create a firstname-lastname slug for them?

Thanks,
Borek

http://ww.wp.xz.cn/extend/plugins/edit-author-slug/