I am getting ready to up pot 2 small fig trees.  I am wondering if I can plant them deeper than the current soil level in my pot?  I am thinking the part that has not previously been in the soil will just produce roots because of the way they can be rooted from cuttings.  What say you?

You sure can. It's a great way to shorten the main trunk of a tree that is a little too tall. The trunk will most likely grow more roots under the soil, it will also send out some branches in the future which will sort of appear as suckers.

Thanks!  That is just what I wanted to do!

Personally, I recommend it.  The more wood under ground the better your chance of having the plant survive a cold snap.  I plant mine at or close to the bottom of the container every time I up pot and if I plant in the ground I try to have only the tips above the ground.