+1 on the wheel bearings. Mine was making that exact noise, only while moving and turning sharply. I replaced both front rotor/wheel bearing assemblies (just finished today) and noise is gone. The big clues are one, it doesn't do it just sitting still and turning the wheels; two, it pops faster if you're rolling faster and slower if you're moving slower. So it obviously has to be something that rotates with the wheel. Being a 2wd, the only thing that does that is the wheel bearing. It's crazy how loud it pops and sounds nothing like a bearing (to me anyway) but it is.
I bought my truck a year ago with 130k on it and the side that was actually bad (passenger) had obviously been replaced not long ago. The driver side was still original and just replacing it did not fix the problem. I'm hoping the early failure was due to improper installation. The spindle nut must be replaced and has a torque of 296 ft-lbs. This is an easy job to DIY, but make SURE you get a 300+ ft-lb torque wrench to do it!!! I borrowed one from work because no auto parts places had one above 250. If you don't torque that nut right you will not get the right load on the bearing. Even if you take it somewhere, make sure they replace the nut and don't just hammer it down with an impact or you'll be back.