I collect jars -- that is, I keep the one with the most interesting shapes with nice, seal-tight lid
I clean those olive or caper jars to reuse again.
I'd rather spoon that extra 1/2 cup of veggies or wild rice in a clean glass jar than a nasty plastic container.
I make my daily salad dressing in a handy jar.
They're also great for stashing items that come in packaging that isn't always user friendly: like flour or quinoa.
And the jars make breadcrumbs or Herbs de Provence as easy as a salt shaker when you're cooking.