I’ve found this interesting read from Kawasaki website while browsing for their bikes lineup for 2011.
This PDF file of Kawasaki Ninja Story 1984-2009 tells how Ninjas has evolved and undergo revolution for lighter weight, better handling and greater design. My favourite Ninja is the ZX-6R. For me, this bike has the balance of lightweight and power which I can say feels like a pocket rocket. Small but fast. But nowadays even the 1000cc bike has weight that almost as light as the 600cc bike with the introduction of aluminium chassis and lighter plastic fairing.
One more pictures and link to download the PDF after the jump