Forgive me if someone else has already suggested this, I don't have time to read all the posts (isn't it wonderful when you get so many responses?).
I bought this book, and it has some great ideas. Maybe you could find it at the library if you don't want to purchase it.
One really simple, yet cool idea, basically, upsize a block from the front into a super size block for the back.
http://www.amazon.com/Over-Easy-Crea...5982990&sr=1-4