Went to Brake Check (*cringe*.. I hate going to chain places like that...) and had their free brake inspection. They told me the front rotors were warped and pads hosed as a result. The rear drums needed turned, but the shoes were OK. Just needed a good cleaning/servicing. Anyhow, they said the "popping" HAD to be coming from the front shocks. Said they were shot. Didn't make a bit of sense to me. I said OK, and said not to bother replacing them -- I could do it much cheaper and with better shocks. The guy said he understood.
So, we left and drove around quite a bit in stop and go traffic -- not a single pop. I have not replaced the shocks yet, but no popping. I thought it might be those rear brakes... I'm going to replace the shocks anyway as the rear ones are leaking.
Thanks again for the help everyone!
Eric