Subject line says it all: nil.id #=> 4 !!! $ ruby -v ruby 1.8.1 (2003-12-25) [powerpc-darwin] $ ruby -e "puts nil.id; puts false.id; puts true.id" 4 0 2 This showed up as a bug in my code when finding records against nil *GOT RESULTS*. I'll need to override NilClass#id. :-/ I can certainly understand rationales for nil.respond_to?(:id) -- everything's an object, etc., etc. But I also might suggest that the id of nil shouldn't be 4?! Shouldn't nil be able to be used as a lightweight and/or primitive Null Object? -- Ryan "John" Platte Custom services, NIKA Consulting http://nikaconsulting.com/