How do you know when the ball joints on your front upper control arms are going south?

When I make a U-turn, or pulling away from a stop with the wheels turned (parking, turns), sometimes theres a noticable "click" sound from the left front suspension. I had a knowledgable friend drive it, and he said "for sure, its not the axle". I have a feeling it could be my damned Ingalls camber links (no matter how hard i try to grease/disassemble them, they still squeak). Or possibly the ball joints...

Please help!