Another Day, Another Project

Here's another quilt I'm working on. I lead the mystery quilt at our quilter's retreat in February '07 using the delectable mountains pattern I found on the 'net. I did all the demo blocks ahead of time and started to put it together at the retreat but lost interest in it when some of the seams didn't line up right. Then, a few months ago I read The Sugar Camp Quilt by Jennifer Chiaverini. It's a story about antebellum Pennsylvania, the Underground Railroad and a quilt the protagonist (I could have said main character but wanted the bump in reading level) makes to help runaway slaves. Inside the cover on the endpaper is a drawing of the quilt. (Click here to see a picture of the author's quilt.) It was basically the same block unit I made for the mystery quilt, the story's quilt is just bigger, but I was nonetheless inspired to work on the abandoned quilt again. I took apart the blocks I'd sewn together and reassembled them in this pattern.

This picture was taken before the blocks were all sewn together, but were just laying out on some of the background fabric. The center space is 12" square and I'm not sure what to about it. I think I don't want to leave it empty, but I haven't come across any blocks I want to use there. I want to finish this top soon, but it has stopped talking to me. Anyone have any ideas?