I love this idea. The creative folks at Melangerie used  little paper shirts, skirts, socks and pants as an alternative to a traditional guest book. From the Melangerie website:

This alternative wedding guestbook encouraged guests to “air out” the bride and groom’s dirty laundry. Instructions inscribed on a detergent bottle prompted guests to write funny stories about Lindsey & Brad on cards shaped like shirts, pants, socks, etc. Guests then clipped the cards to the “clothesline” which was strung at the reception entryway.

We are currently designing a memory book with these cards so notes from Lindsey & Brad’s guests never fade away.

I discovered Melangerie over at Brooklyn Bride.  It’s a  New York City based design consultancy that specializes in curating, creating, and presenting custom gifts, memorabilia and event related materials. Check out the company website for some wonderfully unique wedding ideas. (Love the geneaology seating charts!)