The biggest waste of plastic on the planet....

... has to be, the bits cut off of cable ties.

Or the many plastic bags that separate every cable, remote control, battery, manual, paper or other content from each other in any consumer electronics package.

Then why not collect those parts to return them to the manufacturers.
I'm sure Thomas&Betts will be glad to get those back and find a way to re-use them and sell to you again.

Over here in the Netherlands, the households can separate plastic like bags, bottles and blister packagings and put that out next to the trash in a separate bag.
We assume they then will be recycled to new blisters and stuff alike.
Separating plastic, saves about 2/3 of trash at this household.

Separating plastic, saves about 2/3 of trash at this household.

It's funny you should say that... here in South Africa there is no official re-cycling requirement, so all the rubbish goes in the same big wheelie. BUT there are hundreds of folk who make a living of separating plastic and cardboard from the main rubbish and I assume they sell it on to the waste companies. So we keep a large bin bag going during the week and all our 2l plastic Coke bottles, bread spread tubs etc all go in there. And yep, the one or two bags we put out with the plastic are often bigger in bulk than what's in the wheelie.

I'll start adding my cable-tie offcuts to that bag 8)

It is interesting how some places seem to be able to recycle materials that are not "recyclable" in other places.
For instance, we recycle metal cans of all types, and food/yard waste, and most plastic bottles, but cannot recycle plastic bags. Which is a shame, because quite a large portion (by volume) of our non-recyclable trash is now plastic bags.

Recyclable plastic is worth ~$600/ton IIRC. It's a little less than half as valuable as aluminum.

If I were to wager a guess I would say that plastic bags are not recycled because it's uneconomical to clean them. Putting that another way the RepRap filament-maker projects are able to use bags as feedstock but then their low volume makes it possible to ensure the plastic is clean.

e not recycled because it's uneconomical to clean them

I've read about chemical processes where they heat plastics (even dirty ones) with some catalyst which creates some sort of oil again.
And oil can be refined/filteres quite easily.

quick google:

You might be interested in Bill Hammock's video on what is in landfills:

http://www.engineerguy.com/videos/video-garbage.htm