We were looking to have a 0-minimal environmental impact birthday party. The party was a hit with reusable cloths, healthy snacks and of course cute cakes.
I documented the pros and cons of moving away from traditional birthday party madness in this blog: http://blog.weangreen.com/the-eco-friendly-birthday/
The table cloth that has now been used for 7 birthdays. The girls are so excited to put it on the table on their birthdays!
Anything that is reusable is key. Try to avoid creating waste by making things yourself and using what you already have.