Do you have craft and nature loving friends? Try having a birdhouse building party where you supply the materials and your friends make their own party favors. An American Kestrel birdhouse is an excellent choice. The house is easy to build and Kestrels are found in most of the United States and Canada, so your guests have a great chance of having their house inhabited. Cornell Lab of Ornithology is famous in the birding industry and they have great resources on line. Provide your guests with a handout about American Kestrels and instructions on birdhouse placement. Play fun music while your guests are building, but place bird songs in a surprising place (such as the bathroom) for an added touch to the ambiance. Serve "birdfood" such as peanuts and sunflower seeds. Check out Sendomatic.com for invitations that would match the theme of this party. New Life and Dragonfly would work great. You and your guests will have fun building homes for your new feathered friends.