For the non-Shatnerologist heathens among you, OTS = One True Shatner.
The OTS tells his side of the story on his infamous performance of the afore mentioned Elton John song. http://trekmovie.com/2007/01/24/shatner-talks-rocket-man/#more-449
(you made need to scroll up to get the real thing)
For those who wish to mend their ways and bow before the Most Holy Bloated and Toupeed Shatner, please visit this link