Ginny says "It was shot through the window of our rental SUV as we tried to make a left turn onto Nevada Street in Colorado Springs, CO. I happened to have the camera handy and of course the first thought I had was "Aha! A sighting of a NotTheUnderground sign! Now I can make up for completely missing the one right in my own area".
A bit closer to home we have the roundel being used to advertise a scouting event at Brownsea Island in Dorset.
Thanks to Chris "Awkward" McKenna for sending this my way. Not sure TfL's lawyers will get great publicity from going after some clean living campers, but you never know.
Leo sent in a more commercial spot of the roundel:
He said "Living in the southern part of Holland I travel in Belgium quite a bit and have been regularly passing this sign in a small village near Antwerp. Normally it's difficult to stop there, but this time I spotted a parking place not far from the sign - and I had my camera with me - so here you go.
Underground Lighting shop sells lights and lamps - the funny part is that the underground sign is stuck on top of some computer firm's sign!". Cheeky monkeys.
Many thanks to Ginny, Leo and Chris. I also received an almost roundel from a Toronto restaurant, but they hadn't quite gone the whole hog with a complete rip off, probably to err on the side of legality or avoid paying a licensing fee. Please keep your photos of the roundel coming in and I'll add them to the Flickr set.