Why don't you set up your own (non-standard) challenge, some kind of: "Here are 6 pictures, select those two that show a stop-sign."
You could permutate the pictures, kind of signs and filenames randomly. Other than some kind of mathematical challenge (like in the wiki) this would be somehow related to our subject. You probably could also ask "which picture would you tag as a track?", but maybe that's not always clear without ambiguity... ;) /al _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
