Script Summary: Allows you to change lightness of Geocaching map so you can see caches' icons better.
There're userscripts which allow you to display maps other than MapQuest/OSM on Geocaching.com Map.
But I found that there is little visual problem with it - caches' icons are sometimes too insignificant and one could easily overlook them, especially on very colourful maps.
My script adds slider to change map lightness. You simply set darker map and caches' icons start shining all around :-)
Tested and works smoothly in Opera 11.62