We've been doing lapbooks at our house for a couple of years now. It's really a fun way to organize the unit study and have a culminating project that doesn't take up too much space. I keep them in a magazine file on the end table next to the couch and often see the kids take one out to look through it (reviewing what they've learned!)
I've made up my own and purchased complete kits. But I really love finding free ones online. More and more are being posted all the time.
Below you'll find some links that will help you find one on almost any subject you can think of. By the way, if you don't know what a lapbook is, look at the squidoo site or Jamin's blog for a full tutorial!