I built a community pool lot with the help of Backyard Stuff and those big slip n slides to add some variety. (It also saves me from having to build pools on residential lots, lol.) I put in the public showers from Outdoor Retreat, made a gazebo with a grill, and there's a lemonade drink tray that also came from Backyard Stuff that I put on one of the tables.
I agree a new pool pack would be nice though. :) But you can get creative. If you've got Get Together, you can even make a pool club and such. Didn't GT also come with group actions for the pool? It's been awhile but I thought that kind of stuff was shown off at the Bluffs in Windenburg or something.