Potawatomi13
Imperial Masterpiece
The largest of them, I planted the acorn in my back yard in SF and let it grow for 5 years, chopping once and then again when I dug it out. I had tried to induce roots by girdling the trunk with a wire, but the tree grew over it leaving a circluar scar. In the future I plan to replant the tree in the ground to further thicken the trunk, when I do that I'll girdle it again (with a more effective method) so that I start to get a good root spread. The first photo is from January 2010.
I think you could develop a much more interesting trunk and tree if you cut it off just above the 3 small lowest branches. These could be wired to give some much more interesting trunk lines than it has now.