Ok, the new jewel system is in place. After you find a jewel, it will tell you what city to go to next. You need to zoom in fairly tight for it to count, which should eliminate the "auto-browser" kind of stuff. :)
Someone could still build close placemarks for every city, but I'll be adding more and more cities, so they'd have to keep up.
Plus, once we have 100+ cities, it would take your script a long time to randomly find the jewel - especially when you can just fly there yourself in a few seconds.