Things to knit out of old plastic bags

 Knit a bag http://www.diynetwork.com/diy/cr_needle_arts/article/0,2025,DIY_13768_3059465,00.html
 

Or a 1950s dress

http://blog.craftzine.com/archive/2007/08/plastic_bag_crafts.html

- or some sandals

http://www.pieandcoffee.org/2005/11/17/how-to-knit-a-plastic-bag/