I actually had a little free time yesterday and got a few things worked out on the arm rig. I've got the resizing worked out, did some overall tweaking and then put it into Squetchy Sam to do some more testing. Tomorrow, I'll do some more testing on the arms and see if I can get the legs updated as well.
Here is a quick example model that shows how the exponential decay equation will soften the IK...this version isn't adjustable, it slows the movement of "Bone1" once it reaches 80% of what would be the length of the test arm. Since the test arm is ten inches, it will start to delay/decay at about eight inches.
Once I get things roughed-in a little better, I'll post a more complete setup.
exponential_decay_example_04_08_2010.zip