Is there Wi-Fi Onboard?

I have had quite a few calls recently with people asking about Wi-Fi onboard ships.  Is there Wi-Fi onboard?  Is there Wi-Fi in my stateroom?
For me personally I go away to get away from all of that but for others it is a great way of keeping in touch with family etc.  There are different costs for Wi-Fi depending on the Stateroom and the length of the cruise.
Here are some of the cruise lines and what they offer passengers.

P&O
Available on various decks

Princess Cruises
Staterooms and various public areas

Cunard
There is an internet cafe.  Available in public rooms and areas throughout the ship.

Royal Caribbean
There are six places across the ship and it varies depending on the ship.

Celebrity Cruises
It is available accross the Solstice class ships.  All other ships there are areas around the ships.

NCL
Various spots around the ship.

Fred Olsen
Available on all ships in and close to the library.

MSC
Various spots around the ship.

For any information on other Cruise Lines or for more information on prices etc, please contact me.