Can Taps

Unfortunately, it's all a myth.

http://www.snopes.com/business/redeem/pulltabs.asp
http://www.truthorfiction.com/rumors/p/poptabs.htm

Not too sure about this though:
http://www.zontaadelaidehills.org.au/Lidsforlimbs.html

This could be useful:
http://www.recyclethis.co.uk/20080618/how-can-i-reuse-or-recycle-can-ring-pulls