Reducing trash: re-using plastic containers

Recently I wrote about a website I found called Happy Simple Living and their January Money Diet. Another one of their challenges last month was to find ways to reduce your trash. That got me thinking about all the trash I throw out, not only in food waste, but other stuff. So I started trying to think of ways to reduce some of that. One thing I use a lot of is plastic zipper baggies. Recently I ran out when browning up and bagging hamburger meat and used one of these containers instead. These are little plastic containers that I get when I buy certain sandwich meat at Aldi. They are too nice to throw away and so I'd been keeping them. I found out that they are the perfect size to hold about 2 cups of browned hamburger meat. I also used them for the celery that I chopped up and the bananas that I sliced. 

What ways can you find to reduce your trash?