Serving results based on lookup origin

[Steve King]

Hi everyone,

I want to know if anyone has successfully implemented a bin
installation, based on the theory that:

You have a number of clusters across the globe, that serve the same
application;
Users access your application from multiple locations on the globe;
You wish for them to have DNS results returned specific to their
region (if available);

Ie: If I'm in AU, and I do a lookup for: www.sample.com, and there are
AU servers in my cluster pool, instead of round-robining and pointing
them to a random global server, I'd rather point them to a random AU
server. We can achieve this through modifying the application layer to
check their location and re-direct to .com.au or au.domain.com, but
this is going to cause problems in the long run - and relies heavily
on the ops managing to keep both systems in sync.

Has anyone been able to achieve close to or exactly what I am talking
about? Am I making sense? am I a kook? (I can answer the last one, it
is true.)

Regards,
Steve.