The Spring Fling Party should be held outside by the pool, tennis courts, or any open outdoor space. Serve chili dogs straight from the grill with lemonade to put everyone in that spring has sprung mood.
Prior to the event choose 9 or 18 targets across the complex that you will have the residents travel through. Mark these targets with balloons so they are easy to see from the prior target. Also, create score cards so you can see who got the best score. For added competition, figure out PAR numbers for what it "should" take to get there.
Begin in the clubhouse and have people break into groups of 4 to 6. Send out groups in waves with 5 minute intervals. Players will then take turns throwing their frisbees trying to hit the targets in as few throws as possible.
Talk to key "friendly" residents and see if they would allow their patio or front door to be one of the targets. At those targets provide water bottles or candy and an opportunity to meet a neighbor. You could also make the final hole either back at the clubhouse or at the BBQ grill for hotdogs. Remember: Be careful to avoid making targets in high traffic areas, and avoid fixtures and fragile objects such as lights and windows.
Most of all - have fun with this flexible and easily customizable event.