Diagnosing slight rough idle

[steppinthrax]

I have a 99 Camry with 30K on the engine. When the engine is running and at idle at a stop light or in park there is a slight rough idle. I've checked vacuum lines and such. The RPM needle on the tach vibrates a bit a 700RPMs and I can feel a slight vibration in the brake pedal. When I pop the hood I can see the engine is a little jumpy. I replaced all spark plugs and did notice the overhaul engine vibration was lower but the rough idling problem didn't go away. I don't know where to start. I also don't just want to replace one component after another till it goes away.