What is roller racing? See this description from How Bicycle Rollers Work:

As long as bicycle rollers have existed, so has roller racing. In the early 20th century, audiences both in the United States and abroad would gather to watch contestants compete against one another on stage in timed competitions. In the 1950s, Eddie Wingrave, a British citizen and perhaps the only professional roller racer of the day, toured with a big band and challenged audiences to best him.

The bike courier community has revived this phenomenon in recent years with the advent of Goldsprints. In these loosely organized events — there are no sanctioning bodies and the races often occur in bars — people race against one another on rollers connected to a computer, often in front of other beer-swilling cyclists. Using open-source software and DIY hardware set-ups, the computer counts the revolutions until a racer has reached a prescribed distance measured by the computer. The pool of competitors lessens through several rounds of play.

Instead of standard roller set-up, many of the bikes used in Goldsprint events have no front wheel. Instead, the racers replace the wheel with a fork stand, allowing the rear wheel to glide over the rollers and letting the racer focus on maximum effort over technique. Competitors also use fixed-gear bikes so they can pedal as quickly as possible without shifting. “It’s really a cadence race,” McLean says. “Whoever spins the pedals fastest wins.”

Roller racing has become so popular that Rollapaluza, the world’s largest roller race organizer, is entirely dedicated to this new sport. According to Rollapaluza representative Paul Churchill, more than 15,000 people in the United Kingdom annually take part in roller races, including reigning Olympic champions Chris Hoy and Victoria Pendleton.
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Here’s a great video on the Marymoor Velodrome 2nd Annual Roller Racing…….World Championship..2013

And then there’s this from my favourite cycling comic, Yehuda Moon & The Kickstand Cyclery.