I'm in the process of weight painting on Lani's rig.  For those of you non-animators out there reading this (hi mom!), rigging is the process by which you make the controls for a 3D character to be able to move.  Think of the 3D model as a puppet, and the rig is like the strings you can use to pose it.  You build a simple "skeleton", and then attach controllers to each joint in places where you want it to move, like the fingers or the feet.  Of course it gets a lot more technical and involved than this, but that is the general concept.

Weight painting refines these controls by determining which parts of the character's body can be influenced by each particular bone.  For example, when Lani bends her knee, her leg gets kind of squashed and folded as though she had no muscles in there!  Remember that part in the 2nd Harry Potter movie when Harry breaks his arm at a Quidditch match and Professor Quirrel tries to "help" by casting a mending spell, but instead makes his bones disappear and Harry's arm flops around all gross-like?  It looks something like that...

As you can see in the picture, her shoulder pivots at an angle that is a bit too sharp, and weight painting is the process by which I can smooth that out and make it look more natural.  It can be a long and tedious process so I'd better get to work now.... hope to have some more progress updates soon!