将Silverlight UserControl自定义属性绑定到其元素

I'm trying to make a simple crossword puzzle game in Silverlight 2.0. I'm working on a UserControl-ish component that represents a square in the puzzle. I'm having trouble with binding up my UserControl's properties with its' elements. I've finally (sort of) got it working (may be helpful to some - it took me a few long hours), but wanted to make it more 'elegant'.I'm trying to make a simple crossword puzzle ga