Authority and forwarding, but not recursion/iteration

[Marki]

Hello,

I am seeking a combination of either a combined configuration on one, or 
a config of several different DNS servers together to achieve the following:
* Some clients should be able to resolve authoritative local zones as 
well as some forwarded zones.
* Other clients should be able to resolve all of that _plus_ be able to 
make recursive queries to the internet (or use a global forwarder).
All hosts use the same DNS servers, this should not be made about the 
clients but rather be configurable on the server.

Now the problems are the following:
* Since I need forwarders I can't turn off recursion.
* Since I can't turn off recursion I can't prevent it to go and try to 
resolve from root DNS.

How do I do one (local authority and forwarders) but not the other 
(iterative lookups on the Internet)?

Thanks,

Marki