jessica has a great idea for recycling metal tin cans (you could use those boxes you find at the flea market for some unusual shapes too) she blogs, "i took these old tin soup cans, drilled some drainage holes in the bottom, and made planters for some little succulent plants i had. they look really really cool when they start to age and rust."
i recently read somewhere that recycling one aluminum can saves enough energy to run your tv for 3 hours.
want more ideas? read "use your garden to recycle just about anything."