Screw-On Caps for Plastic Bottles (100 pack) — Toronto Brewing
Recyclepedia | Can I recycle plastic bottle caps?
TerraCycle
Amazon.com: Minelife 100 Pieces Plastic Bottle Caps Protection Bottle Lids, Decorative Bottle Cap for DIY Craft Environmental Protection and Development of Children's Intelligence (Mixed Color)
The Future Bottle Caps will be made from Bioplastics