These guys at NIL continue to impress me. I originally met one of the NIL staff when I was running a BGP lab at Cisco Networkers a couple years back. We sat and talked about regular expressions with each other while the Networkers folks hacked away at the remote NIL equipment. Ever since then, I've glanced at their website from time to time - they just added a great post on migrating routing protocols:
http://www.nil.com/go/ChangingRoutingProtocol/
While you're there, you can find a wealth of other "best practice/cool tips" articles they have on-hand. This was the first place I learned about the Configure Replace command...which I've found doesn't work as well in practice as it does in theory. But that's another post :).
