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.