They Used -What- as a Bookmark? by birdie

Always good as a conversation starter...the things people leave in books that are not traditional bookmarks. Thousands of dollars, a Christmas card signed by Frank Baum, a Mickey Mantle rookie baseball card, a marriage certificate from 1879, a baby’s tooth, a diamond ring and a handwritten poem by Irish writer Katharine Tynan Hickson are just some of the stranger objects discovered by booksellers. And then there's the strip of bacon.

Abebooks has a listing of these items...some mundane, some bizarre, some deeply personal. What have you found?