If you're trying to reduce your carbon footprint, don't just go orange and black this Halloween. Think green. Choose invitations that are printed on recycled paper or tree-free paper (some made from elephant poop!). Also consider seeded paper. It germinates when you plant it, making it both reusable and recyclable.
If you'll be hosting a relatively small number of guests consider turning your invitations into a fun craft project for the kids. Paint important party invitation information onto small pumpkins or gourds to transform them into invites - when the party's over, toss 'em into the compost pile.