A319 flight crew reports wake turbulence encounter at 3500 FT on departure from preceding B767. Encounter causes mild jostling and a momentary compressor stall. Crew elects to return to departure airport for over weight landing.

Narrative

We departed runway following a heavy B767. Passing about 3500 FT AGL we encountered some rough clear air turbulence from the heavy B767 and then a very loud bang occurred. Engine number 2 started to roll back and we got an ENG 2 COMPRESSER STALL ECAM. The engine recovered thrust as we climbed to 4600 FT. We declared an emergency and requested a return to ZZZ. My co-pilot started to run the appropriate check lists as I called ATC with all our information. I made a PA and the flight attendants were informed of our problem and course of action. No cabin advisory was issued. We landed with no further problems. Taxi to gate was normal. The landing was over weight with about 100-200 FPM descent rate at touchdown. Maintenance; emergency crews; and support personnel met the aircraft. All personnel involved performed in a professional manner. Supplemental info from ACN 831946: After departing behind a B767 we encountered a slight wake turbulence passing through 3500 FT. At about the same time; we had an engine 2 compresser stall and noticed the stall ECAM momentarily as the engine came back to normal. The Captain talked to ATC and flight attendants while I ran through the appropriate checklist for the stall and overweight landing. The return and landing were normal given the circumstances.