Honey ! How much Currency for our cruise

Going on a cruise is a wonderful experience and the longer the better and they tell us it is an all inclusive price. Just drop your bags once in the cabin and no more worries.
Well, a few exist. One is the how much do I tip or not tip or do I use cash or what is expected of me.
In the vast majority of Cruise Lines , excluding the mixture of passengers of varied tipping cultures , your Credit Card of choice or manner of payment for ship expenses will be credited each day with an amount on average of $10.50 – $ 13.00 US a day per passenger. This is called Auto-Tipping / Gratuity for your convenience, which you can adjust at Ship’s front desk.
Numerous articles exist for and against.
http://cruisetip.tpkeller.com/ This one calculates tips based on Ship, Voyage Days.

http://www.cruisecritic.com/articles.cfm?ID=132 One of many links as to a guideline.

The world is about to change as we onboard more cruisers from Europe and Britain.
http://www.timesonline.co.uk/tol/travel/holiday_type/cruises/article6952104.ece

The other item in this world of credit cards , debit cards, prepaid trip, travellers cheques is how much cash do we need when we go ashore, what currency should it be in for, guess what, tipping the guide or buying an item in the market ?
In Europe the Euro helps as it is standard including Ireland while in the UK it is the GBP but that can vary also in the type of note given you as in a Bank of England note or say a Scottish Note.
Most ships will offer local currency exchange at a price but the US dollar seems to be the accepted norm if all else fails.
Thoughts??