I use that tool for some of my photos when I've taken a distant photo of the skyline and see something sticking up that I'm curious about. If you plot the line from the spot where you took the photo to another point behind the object you're curious about to whatever building you know on the skyline, then you can follow that line and figure out where it's located.
There have been times before when I saw a roof of a building that I didn't recognize and used that tool to find it that way.
It's also great for finding good vantage points for taking photos of the skyline. If there's a certain angle you're wanting of the skyline so that it shows a specific building, you can use this tool to find a parking garage or hill where you could do that. I've also used it many times to figure out where someone had taken a photo of the skyline when I wanted to see that view myself.
And oh, yes, welcome, OtherKevin.
