These little earth themed sugar cookies from http://www.organicbouquet.com make the most adorable wedding favors.
Try this tip from Martha Stewart:
To turn these adorable cookies into a charming centerpiece, simply place flowering branches in a sturdy vase. Wrap cookies in cellophane bags and ribbon, and hang from branches. At the end of your party, add signage that instructs guest to undecorate the tree and take a cookie with them.