Group Combat Assistance
Some group is about to launch some assaults on some Raider camps (maybe 5 locations). You get involved as the guy whose Pip-Boy has the locations. You go to the Raider camp, call in the group with a radio, they show up and you all fight. Go to next one, repeat. You get paid based on kills and group members left alive.
Groups: BoS, Hub Patrol, NCR Army, Junktown Scouts, etc
(Calling the rest of the group would not be via a distress signal. You just call them on a random 5-digit channel they give you and they find you via their secret triangulation methods. This should minimize PK disruptions.)
Locations: can use existing large random encounter maps but populate them with Raiders, add a tent and some raider standards/flags, and give new spawn point in lower right corner behind some rocks.
Repeatable as you get more locations. Pip-Boy gets updated with new locations as you find certain "wanderer NPCs" in random encounters. Then you go talk to the group commander again about launching another assault campaign.