Yeah I did this once in Junior High with a buddy. We were talking about sex one day, both of us got hard and wanted to compare sizes. When we did we wound up watching each other jerk off.
Recently, I met a fellow hiker online. We live a couple hours apart but managed to meet halfway on a trail. We found a secluded place and watched each other jack. When I can I do it online and phone. It would be nice to hear from anyone else interested.