Thanks guys! It's looking a little overgrown right now. I'm waiting until I get back from the Delaware County Auction and examine my spoils before I rearrange/adjust the tank. I've had the pennywort for about 2 years and it's one of my favorite plants. It actually doesn't uproot very often.
You can add some lead weights to the center of the stem so that it gets pushed down. With that you will get the plant growing at both ends of the stem.