I take burning gas very seriously--as in, I pretty much try to avoid it. So even when I find so much stuff that I can't get it all home on the bicycle, I think hard and carefully about going back to pick it up in my old truck.
Out riding today, though, I discovered enough stuff in four nearby Dumpsters that I decided it was worth a return trip by truck. As it turned out that round trip to the four Dumpsters covered exactly 3 miles--and since my old truck gets about 15 miles to the gallon, my mental calculations tell me I burned 25.6 ounces of gas--less than a quart. Here's what I hauled home at the cost of those 25.6 ounces:
A seven drawer desk (minus the middle drawer). A big roof-top skylight, double-paned. Lengths of angle iron and six cast iron window sash weights. An aluminum shower stall. Two pieces of pegboard. An ironing board. An attic turbine. A large coil of copper pipe, insulated. Some other bits of scrap metal. And a reusable cotton 'World Market' shopping bag.