I save any container I use. Every jam jar, ketchup bottle, soda bottles, and anything else that I can wash clean. I even keep all my t.p and paper towel rolls. I am NOT a hoarder! I'm crafty :-)
I open a paper bag (which can also be used as a toy) and fill with like containers. I set my paper collector bags in the garage except the t.p roll bag that's under the bathroom sink. Whenever I need an extra container I can have one on hand, it's handy.
So when my children say I'm bored I will let them choose some containers or just give them the whole bag depending on how full it is.
You wouldn't think trash could equal hours of fun but it can if you add imagination.