Lately I often needed to tune assembly binding redirection. Since I am lazy person, I would rather write programs to help me write programs than write programs. 
So that’s how this little tool appeared.
It can add or remove binding redirection records in both frameworks 1.1 and 2.0. A typical call looks like tihs:
assemblybinder SomeAssembly /lower:1.0.0.0 /upper:9.9.9.9 /target:2.0.5.0
SomeAssembly is, by default, a name of assembly in the GAC. Also it can be a filename, either absolute or relative to current folder.
The rest of details you can get from the sources
UPD: Here is SVN repository of the project – http://assemblybinder.googlecode.com/svn/