The most interesting thing I’ve done as a Local Guide is a story about a monument.
When I moved to the US, I started to discover neighborhood. One day I was walking across New Brunswick, NJ downtown and found out a monument to the firefighter. I took a photo and later in the evening decided to contribute it to the Google Maps. It was surprising but I didn’t find the corresponding object on the Google Maps to contribute this photo to. I thought “Wow, that will be the first new place I will contribute to the Google Maps!”. I started to google using “Search by picture” feature to figure out anything about this monument. And I found it, a local news article that described some details about this monument, at least the year it was created, the author, the purpose. Having that I made my first contribution of a new place to the Google Maps, and Google approved it. I was proud of myself…
Just a couple of weeks later I was driving by the place the monument was installed. I took a glance at the source of my pride thinking “Heh, I’m helping others to know the local history!..” - and found out that the monument has disappeared!!! 
“Hey! I have just added it to the Maps!!! How? Where?? When??? It’s unfair!!!” - that was a fiasco
I tried to find any references and answers in local news, but didn’t find anything…
Some months later I was driving through another town in neighborhood, and it seemed to me that I saw the same monument in front of local Fire Department. “Oh, here you are! You just moved to another town, another Fire Department, to give honor to another firefighters…”
…at least, I want to think it was the same monument.
…and at least I helped to myself to know the local history better, because it pushed me to find information about the photo I initially took, about this monument. If it worked for at least one people, then it works!