It was ridiculously easy to create these sits for the Whimsy Sungate.
I rezzed two prims, turned them into spheres, reduced their size to 2.5 x 2.5 x 2.5 meters, set the texture to blank, made one blue (for men) and one red (for women), and added some shine.
I then dropped a simple sit script in the prim and added a sit sound the script called for. I had to tweak the scripts a bit (for one thing the script didn't turn the balls alpha when avatars sat) , but the most difficult part was finding appropriate poses.
I settled on a female pose that gently lowers the avatar to her knees, and an insouciant male pose in which three of the avatar's limbs hang into space. And I was done.
I'm going to build a script dispensing device at our Suborbital Asteroid Retreat up at 4000 meters, but I'm going to rework the script so it automatically calls a pose placed in the ball so no scripting will need to be done (other than resetting the scrip; some to think of it, I'll have the script reset itself whenever the prim's contents are changed. If you would like a pose-ready ball, send me a notecard or an IM and I'll be happy to send you one. Just remember it might be a day or two before I can whip the script into shape. When you get your full-perm copy, just drop an animation into it and hope for the best.