Can anyone suggest sustainable and affordable material(s)?

Question:

Can anyone suggest sustainable and affordable material(s)?

I am a student-designer who is presently working on a series of tables. What I am looking for is a material that can be cut easily and is sustainable/environmentally friendly, durable, and affordable. I live in New York City and therefore would prefer it to be accesible either directly (I'd be glad to pick it up!) or through (quick!) delivery. Also, though I am open to anything from plastics, resins, bamboo, compressed paper, etc., I need something that can come in "sheet/ply" form (as in a tabletop.)

I'm open to everything, I just want it to be as affordable as possible and to look really nice. I do realize I haven't been too specific -- I feel as though that will allow for the most potentially hopeful answers. THANK YOU!

Best Answer - Chosen by Asker:

There is a recycled decking material made from compressed saw dust and resins. It's brown like cardboard...and Its looks are those of an...oh... artificial decking material. It's waterproof and very durable. It is not load bearing however (it could only be your table top, or a bench seat or the like.) Basically these would be eco-friendly planks of wood. I don't know what they call it, but it's been turning up more and more. Any lumber yard/mega hardware store would have it. I know I've seen Home Depot in Manhattan.