I saw the hallowed out orange idea, filled with yogurt or jello. I tried it, but the orange looked shriveled the next day (not very appetizing). I read about the idea of string cheese attached to a pretzel stick for a witch's broom on the internet? Anyone ever tried that? Any other ideas? Thanks.

apples decorated like pumpkins

http://www.tipjunkie.com/creative-halloween-party-food/
http://belladia.typepad.com/crafty_crow/2008/10/halloween-par-1.html
http://stephandjoe.blogspot.com/2008/10/mummy-weiners.html
http://superpunch.blogspot.com/2009/09/jell-o-metroid-and-more-halloween-food.html
http://www.ghoulfriday.com/gator_heads

Are clementines out yet? They could be cute small jack-o-lanterns, and they peel easy. Is it for young children? Or cheese & crackers, cut pumpkins out of orange cheese and ghosts out of white cheese. I've also seen soft cheese made into pumpkin shapes with a pretzel stick for the stem. Or caramel apples.

Scroll down for white chocolate covered strawberry ghosts: http://athinday.blogspot.com/2009_10_01_archive.html
At the bottom of the page, peanut butter (or cheese) cracker spiders: http://www.iamwellness.net/wesp.html
MummyDogs (I'd use a food coloring marker for the eyes): http://www.fitwoman.com/blog/2008/10/halloween-healthy-recipe-mummy-hot-dogs.html

Good luck!