A friend of mine used to go dumpster diving by a grocery store and found tons of food and chocolate and stuff that was often just thrown away because they needed the shelf space, not even expired.
Around here all the dumpsters are indoors or locked, so it wouldn't be possible even if I wanted to. I don't think it'd feel right digging around in someone's trash so I probably wouldn't do it, but maaaaybe. Depends on what kind of trash. If I had access to a dumpster belonging to an office or tech related building or something, where you might find expensive equipment (often fully working but just old, sometimes broken but easy to fix) like EEVBlog, that would be pretty interesting to see what I could find, and I wouldn't really have to dig around since often they'd just be laying on the top.