Polycarbonates main building block is: BPA - bisphenol-A
Think all plastics w/ the recycle code of 7... plastic water bottles.. not going to name names, but the ones we all use. I know they have created or are working on a bottle not made of BPA.. apparently other plastics such as high-density polyethylene (#2), Low-density polyethylene (#4) or polypropylene (#5) which are thought to be safer and not to leach into your food.
I recently ditched all of my water bottles and replaced them w/ a SIGG bottle (http://www.sigg.ch/) ... thanks in part to my good friend Julie.
BUT it doesn't stop there.. I was disturbed to read in this article that BPA is commonly used to line the inside of both cans in canned goods and milk cartons. I would hope that the manufacturers of organic milks would be wise to this risk and not use BPA, but how can I know.. so are we going to have to go back to buying local and in glass jugs... then recycling the jugs.. that's probably the more environmentally friendly way to go anyway.
I won't even attempt to describe what BPA does to you, but you can check out this wikipedia listing: http://en.wikipedia.org/wiki/Bisphenol_A It's something to do w/ Estrogen receptors and is starting to be linked to the increase in breast cancer.
So replace your water bottles.. you can also check out klean kanteen... and stop eating canned food (fresh or frozen is better anyway) .... and I'm not sure what to do about milk (and any other food items that may be packaged in this stuff) aside from the glass jug thing. I did just read that Whole Foods (aka whole paycheck as Tom likes to call it) has stopped selling items packaged in BPA as of sometime in 2006.
Other plastics to watch out for:
PVC - plyvinyl chloride - #3 - commonly used in kids toys - think teethers.. GREAT! Try wood toys I guess - Haba toys are pvc free: http://www.oompa.com/cgi-bin/category/Baby_Toys
PS - polystyrene - #6 - styrofoam (but we already knew that was bad stuff) apparently the production of that stuff is real bad for the environment (like my technical jargin?)