We found a source for local milk that comes in glass bottles that are then returned for a refund.

For plastic milk jugs: — fill with water, use as weights — make compost tea in them for your garden — use them as plant watering cans — rather than buying packaged drinks, reuse with powdered form — store cold coffee for later / iced tea?

Just a few things off the top of my head - agree, they start to pile up and become a problem, which is why our best option is to eliminate them.