Have been having a little bit of a play tonight, on the basis of what you're doing with the bing maps.
I have been gathering data recently of updated GPS readings, descriptions and photo's of the caves, mines and sinks on Minera mountain and the surrounding area. The data that has been put onto the linked map is some I took from the UCET knowledge bank for an example and to see if it would work.
There are 59 entries so far and does the same as your bing maps does (see below).
mapsengine.google.com/map/edit?mid=zy5AL-oT859g.kl1GTktgJM0U
I'm not trying to better anything here, but for some reason I can't sync Bing maps with my phone to see the plots out and about. By using google however, it allows for you to sync the labels to your memory and your GPS will take you there or, like a GPS device, will tell you when you're about to approach something already on the system - I'll screenshot this later.
Also, if anybody wants the newly collected co-ordinates for the Minera mountain and other places i've taken a GPS you're welcome to it - i've found many being miles out and descriptions in the recent years from Caves of North Wales are now outdated due to digging and natural changes.
I either need a girlfriend, or need to sort my life out! It's Saturday night!
Tom