Can't shake it off.

I have a 2000 Toyota Camry, 109000 miles, all maintenance up to date and vouched. I have a vibration coming from the car but can't pin point it. When I hit the brakes it feels like the brakes are temporarily applied then stopped but in rapid succession. I replaced my entire front end to include half shafts, tie rods, wheel hub bearings and struts. I also replaced the rear wheel hub assemblies thinking that the vibratioon could be coming from the rear. I also had the car aligned recently and am about to replace the tires as they were chopped up by faulty struts. I still have the vibration and don't have a clue as to what it is as well as the braking problem. Can they be related? What do you think?