GAC Scope: why does it override local assemblies, and is there anything we can do about it?

I spent some time fighting the GAC today, as a result of which it completed the local build in my application directory, and I thought it was strange that the GAC “ranks” the local file; in almost all cases of development, the local region surpasses the global region.

Why is he doing this? This seems controversial. How can I get around the problem if I have several assemblies of the same assembly (but with different tokens) and I want to use one that is NOT in the GAC?