Terri,
My boys each have 20 minutes to choose something for the other boys to play together. My 3 oldest boys do this, while my youngest is napping upstairs. This takes up an hour or more of their afternoon after school is done (and comes after our one-hour recess). When my kids were younger, we had a 30 min. time that they each chose something for the others to play. However as my kiddos are getting older, they each desire more of their own free-time in the afternoon. So, after they have played together now they each have their own free-time until our afternoon rest time before supper.
We also do still have a 45 min. rest time in their rooms in the afternoon right before supper (where they can play quietly, create, read, listen to books on audio with headphones, latch hook, etc.). In this way it's quiet for me right before supper, and I have time to prepare it (or think

) without all of the kiddos around!

If we skip rest time, we find especially the little ones quickly derail in the evenings. So, we work hard to make sure everyone gets some quiet time before the evening meal.

(Mom included).
For their 20 min. play time, the boys can pick anything from playing a board game, to playing outside, to creating with art supplies, to playing with some sort of toys in our playroom (like Legos, K'nex, Playmobile, G.I. Joes, castle, build huge train tracks), to playing with our game table (new this year for Christmas), to recording books on tape or cd, to flying paper airplanes, to using their foam dart guns, to playing cards, to racing cars, to writing and illustrating stories together, to making puppet shows, to making short videos with their cameras, to playing in our Playhut type tents and tunnels etc.

I set the timer (or have the boys set it), so each activity is only 20 min.
They must not be upstairs where the little guy is sleeping, they must not be running through the house or be incredibly loud, and they must all play together (not one child off by himself reading or something), but beyond that there aren't many rules for this time. The kiddos are usually required to pick up at the end of each 20 min. segment. However, sometimes a child will want to continue playing with his choice later. Then, we'll allow those things to be left out.
I am always nearby to oversee but am doing my own tasks.

The boys have done a great job of coming up with their own ideas as the years have passed. If they're not sure whether something is appropriate, they'll ask.
Hope that helps!
Blessings,
Carrie