One of the towers at the Adobe headquarters has a sort of semaphore on top that displays coded messages, and spins whenever a plane flies over the building:<p><a href="https:&#x2F;&#x2F;www.adobe.com&#x2F;aboutadobe&#x2F;philanthropy&#x2F;sjsemaphore&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.adobe.com&#x2F;aboutadobe&#x2F;philanthropy&#x2F;sjsemaphore&#x2F;</a>