local administrators are sharepoint administrators

Now I work for a company as a tier 3 support person. I have because of this
domain admin rights. By default domain admins are put in the local
administrators group on each server. this means that most of my colleagues
for whom I am trying to set up sharepoint portal server are also doing the
same thing and can all administer sharepoint.

I realise that we may be unusual but this does present difficulties.

Is there any way around this at all ??

Thanks
Alastair