C# implementation of deep/recursive object comparison in .net 3.5

I am looking for a C# specific , open source (or source code available) implementation of recursive, or deep, object comparison.

I currently have two graphs of live objects that I am looking to compare to each other, with the result of the comparison being a set of discrepancies in the graphs. The objects are instantiations of a set of classes that are known at run time (but not necessarily at compile time).

There is a specific requirement to be able to map from the discrepancies in the graphs, back to the objects containing the discrepancies.

I found a really nice, free implementation at www.kellermansoftware.com called Compare .NET Objects which can be found here. Highly recommended.

Appears to have relocated to github - most recent version is available here

This is a complex area; I've done some things like this at runtime, and it quickly gets messy. If possible, you might find that the simplest way to do this is to serialize the objects and compare the serialized form (perhaps xml-diff and XmlSerializer). This is complicated a little by the types not being known until runtime, but not hugely (you can always use new XmlSerializer(obj.GetType()) etc).

That would be my default approach, anyway.