Paint ball protective gear
Goggles, a cup and a throat guard are a must. We trained at the academy with paint balls of a different nature: 9mm Sig with paint loads. We also trained with 12 guage shotgun paint rounds and uzi's with paint. Those things travel almost the speed of a .45 round. I got tagged once in the shoulder by the uzi and it was bearable. I can't imagine the pain if my throat got hit or I took a direct shot to the goodies!
"Regulation" paint balls are slower, but take the extra caution anyway.