Compare Titanic to Costa Concordia :: 100 yrs apart - what have we learned?
Titanic has 19th century tech but barely able to use it to the fullest ( wireless radio - morse code - very small message payload - poor distress procedures & discipline in industry). Used 18th c. tech - flares to signal distress - but ignored by closest vessel. Left the ship watches binoculares in port (I've done that). Capt'n made errors in judgement - full steam ahead through known ice flow with no binos on watch... stupid move.
The Costa Concorda's captain made several big blunders in judgement. He may wish he had gone down with his ship, as Capt'n Smith of the Titanic did.
While both captains made blunders of judgement, the state of the art of sea distaster has changed in 100 years. The two disasters are not very comparable on the environmental factors - icy north atlantic waters vs. Mediterranean sea close to shore.
On the Titanic no one had a personal communication device. Quite frankly by today's standard it would be hard to call the ship's radio room a communication command center at all. I would assume that passengers on the Costa Concorda made personal distress calls.
In any type of emergency the ability to communicate is the number one priority and the highest value assest to insure safety and assistance.
Here's a good spot for a plug for the Divers Alert Network (DAN) it's not just for scuba divers.
So what have we learned in 100 years. To use our power of communication - over long distances - in real-time (not async like morse code or twitter) - oh, and don't leave idiots in charge.