Colludium - That is what I'm looking for. I had a post about finding surface angle (normal) a while back. Ashley asked why I needed it but then never got back. I am pretty sure the system could tell you this info, I know physics can tell you this as well, and I can create it myself by mucking about with object sensors and different object types with a known slope on one side.
I just prefer elegance though. and any system I make requres alot of placing of objects in the editor.