London's transport is a bit funny as there are quite a few options that all seem about the same but are run by different companies. The tube. The overground. The tram. The bus. The crossrail. The rail. The TFL rail. The Thames Clipper. and then there is the Emirates Air Line.
Time Lapse London video, I made it a priority to take a trip to the cable car. Check out the video... it's really neat, especially if you are familiar with London and its stuff.
The Emirates Air Line opened on June 28, 2012. It normally takes 10 minutes to cross the 1km distance over the river, but during rush hour, the time is decreased to 5 minutes.