Bumping for great justice. This needs to be known.
This is such a useful tip. Definitely using it for my next project.
What I'd like to add is that your source stockpile for feeding the carts, make sure to have it empty of barrels and bins, that way, you won't have a derped-dwarf piling it and then auto-dumping it in an endless loop. Alternatively, you can also delete the links that give to the receiving pile. It doesn't hurt to have a single gathering pile with divisions spread between, or have a condenser dump cart (big collection stockpile into a single quantum (exclusive link only), and then separate by type from there (separators linked from condensed)).
SP = Stockpile, U = Minecart, C = Condensed SP, XYZ = Divisions
.... .→ UX
.SP. → UC →<-→ UY
.... '→ UZ
This works excellently for farmlands and seed storage, condensing refuse, as well as separating bones from it, making a more proper food court, optimizing production centers; the list goes on. Find out what you can do with condensation.
@UDV: That's really good to know. Speeds up producing them big time.
EDIT EDIT EDIT:
Awesome idea: Food court/vending machines/garbage cans, and regular intervals of cleanup.
Basically, take this AQS system, and modernize parts of your fortress this way utilizing Z-levels and this method to your advantage. For example, in a level above your cafeteria, you have your kitchen and still and their modest food stocks (made sure to not be included in the main deposit stockpile); have them produce their goods, and have minecarts set in certain points of the cafeteria to dump into a single spot accessible from that one room, but not the production centers; making effectively, Vending Machines. On the same level as the dining hall/cafeteria, place a refuse/seed stockpile receiver in a similar manner to the production zones'; making a Minecart 'Garbage Can'. Below that, you have a path to your refuse AQS and a shorter path to your farm's seed storage/granary. If you want, all the other production facilities can you the same system for streamlined production; or at least, aesthetically make it look more industrialized.
Fortress Waste Management Mode = Place 'garbage cans' all over the fortress, and have maintainence hallways serve as collection points to the main collection zone to be sorted out (if you have mods that take advantage of refuse (Wasteland, for example), you can further process it, or otherwise burn it, use the miasma to torment prisoners, or load your shotguns; assign seed dumping while at it for those pesky leave-behinds. Central shafts work wonders in this regard (one or two 'garbage cans' from a hallway and dining hall, one from butcher's, and one more from military barracks for limbs and over-damaged armor/weapons/etc.; and why not, a corpse-shaft for fallen comrades. All sharing about 2-4 Z-levels; and provided it's not taken advantage of from invaders, a dump point for collecting combat spoils, and cleaning the field quickly.).
This can really help out for keeping your prisoners fed; just as long as you regulate in/out flow of goods/garbage.