Pros: Incredibly strong and lightweight. Riding ti is like being carried across a land of down duvets while on opium by herd of Jell-o horses all riding lugged steel bikes with Clement tubulars.
Cons: The vast majority of titanium bikes are built of tubing purchased from breakaway republics that were once part of the former Soviet Union. These republics subsidize themselves by dismantling their nuclear weapons facilities and selling the space-aged materials of which they are comprised to the West. The result is that most titanium bikes emit unacceptable levels of radiation. Owners of titanium bikes are transforming their DNA on every ride and are unwittingly spawning an army of mutants even as you read this. In an already uncertain time, this is, quite frankly, horrifying.
http://bikesnobnyc.blogspot.com/2007/08/bsnyc-used-bicycle-buyers-guide.html