Starting last Sunday, Eli has been sitting up with NO HANDS. His balance is still a little off, but he can now pick up toys and play with them while sitting. Mom loves his new skill because now we can sit across from each other and do hand games. He loves them, but not as much as I do. Here is Eli's progression.
He started off by holding a ball or block in his lap and resting his hands on the toy.

He moved into having one hand hold him up while the other hand would wave in the air.

Then, he started to put both hands behind him while he leaned forward to balance himself.

Here he is sitting up biting on his blue moon, which is currently his favorite toy. He can sit up for a few minutes now without tipping over.

Also, Eli is getting on all fours all the time now and he rocks back and forth. But, he still uses his head to help him scoot forward.