A 23-year-old woman from Singapore recently broke the record for fastest text message (previously held by a Brit):
Contestants had to type: “The razor-toothed piranhas of the genera Serrasalmus and Pygocentrus are the most ferocious freshwater fish in the world. In reality they seldom attack a human.” Using the phone’s predictive text function — that guesses words as letters are typed in — was not allowed, and the target phrase’s punctuation needed to be spot on, too.
She whipped that badboy off in 43.66 seconds, without any predictaive text fanciness. Of course, I’m not sure how much help the text prediction would be on ‘Pygocentrus’. Her age surprises me, though. I imagined that she’d be 15. SMSing is like professional tennis or figure skating, but worse. Once you approach 25, you’re over the hill.
DarrenBarefoot.com 
Apparently, in areas where texting is widespread (Europe, Asia), young people are more likely to push doorbells and elevator buttons with their thumbs than another fingers, because they have become so strong from punching out messages on phones.
Could be an apocryphal story, but it sounds good anyway.