It possibly could be the front rubber bushings attaching the guid rod mount to the ower control arm. Or, the most likey thing I think at this point would be the ball joint on that side. I have only seen ball joints last about 80-120k before they really show signs of wear.
I would also definitely get it aligned, but only after you find what the popping is and fix that as it's likely you'll have to tear down soem steering/ suspension components to fix.
Have fun, let us know what it is.
Adam