The "Touch Tone" telephone was standardized when the dual-tone multi-frequency (DTMF) system in the new push-button telephone was introduced in the 1960s, and replaced the rotary dial. When used to dial a telephone number, pressing a single key will produce a pitch consisting of two simultaneous pure tone sinusoidal frequencies. The row in which the key appears determines the low frequency, and the column determines the high frequency - hence the name dual tone mutli-frequency. Canon 40D, 1/20 sec @ f/2.8, ISO 800, 50mm macro.
From 365 Project The Air Force Memorial in glows against low hanging clouds and mist. Located on a promontory in Arlington, Virginia, overlooking the Pentagon and adjacent to Arlington Cemetery, the memorial's three 270 feet tall stainless arcs evoke the spirit of flight. Taken with a Canon 40D, 5.0s exposure at f/8.0, ISO 200, 28mm equivalent focal length, mounted on a tripod.
This is a reproduction on an early 20th Century "squirrel cage" carbon filament light bulb built by Thomas Edison. In today's modern reproductions the filaments are made of tungsten, which burns three times brighter than the original carbon filament versions. They are really getting popular in vintage bare blub fixtures. This one was hanging over my table at Tarrant's Cafe , 1 W. Broad Street in Richmond Virginia. Canon G15, 1/15 sec @ f/8.0, ISO 200, in macro mode.