For those that haven't used this yet, it looks to be rather promising. There is a new (relatively speaking) Autodesk site called Autodesk Seek. It Seeks out digital design content.
:/ Sorry - couldn't resist. Check it out here: http://seek.autodesk.com/ While they don't have much in the way of 3ds MAX files, they have a ton of Revit families, IES files, etc. What you can put in Revit you can transfer to 3ds MAX via FBX, so technically you have a bunch of 3ds MAX files to, just in a round about sort of way.