This DIY will show you how to make a planter from nearly all recycled (and free) products which will pretty much water itself. Without giving them much attention, you can grow your own herbs, flowers, or other plants. You can continue to re-use the planter, or simply recycle it when you're finished.
We've seen some pretty innovative repurposing of plastic bottles lately, like that self-watering vase and Michelle Brand's ethereal lights, room dividers, and light shades made from the bottoms of soda bottles. But, what's so wrong with reusing them for their original purpose — storing liquids? Absolutely nothing.