Roger just IM'ed a link to his blog: http://rogeralsing.com/2008/02/26/linq-expressions-access-private-fields/ where he removes the need for reflection to access private fields by creating an expression tree instead. Reeally cool and a lot more performant then reflection:

"The Reflection.FieldInfo approach took 6.2 seconds to complete.
The Compiled lambda approach took 0.013 seconds to complete.
That?s quit a big difference."