The Geico insurance company maintains a team of skywriters based in the northeast. The Skytypers, as they are called, fly in a six-plane formation and form letters by selectively releasing bursts of smoke, producing what appears to be typewritten letters in the sky.
The group also performs at air shows as seen here at Jones Beach on Long Island, NY. The skilled pilots get precision performance out of their big, heavy WWII-era SNJ trainers. What can't be communicated via photo is the deep, characteristic road of their radial engines.