The longest word in English has 189,819 letters and would take you three and a half hours to pronounce correctly. Seriously. It's the chemical name of Titin (or connectin), a giant protein "that functions as a molecular spring which is responsible for the passive elasticity of muscle." You can listen to a guy pronounce the whole damn word.
Supercalifragilisticexpialidocious this is not. In fact, you would need to say Supercalifragilisticexpialidocious over 5000 times to come close to this word to come close to matching its letter count (go ahead, I'll wait). If you want to see the word spelled out, it looks a lot like this:
That's just the first part of the word too. The whole thing can be found in a 65kb textbit file here. You're going to be scrolling for a very long time. For reference, the internet says that Pride and Prejudice has about 120,000 words and the New Testament has about 180,000 words. And if you're bold, you can watch the video above where the guy actually pronounces the whole damn thing (the flower doesn't survive the pronunciation). [Geekologie via DesignTaxi]