So I looked through the last 10-15 or so of the xkcd comics, and maybe 3-4 of them were what I considered HN material (Feynman, this one, etc) and a bunch that were not (tripping band kids, punch buggy, tapping, etc). The appropriate ones (like this) have a lot of upvotes, the others don't. I'm happy to announce that the system is working, the good ones are rising and the bad ones are getting ignored.
Remember, commenting to complain about the bad ones makes them rise to the top of the front page!
Well, just to argue against my original point, the scaling of the travelling salesman problem usually applies to the time taken to figure out the optimal route, not the time taken to actually traverse it, which is O(N). If you're just looking at the route-planning stage, then the "sod it, I'll just sell on eBay" algorithm is indeed O(1).
The reviews on ebay are turing complete. You might think people are giving over the top reviews with their "A+++++++++", but that's just unary notation.
Remember, commenting to complain about the bad ones makes them rise to the top of the front page!