Mars has water. Not a lot, but it may be enough. And if you use some solar panels to pump electricity through that H2O, you'll have some H fuel and O to breathe. But yes, it's not as nice as landing on a tropical island. However, tropical islands don't have drinkable water (unless you manage to find a spring), and don't really have food, unless you feel like chewing on vines and bark. So, although it looked prettier, back then it was rather inhospitable as well.

Bandyopadhyay and colleague Susmita Bose were already well known for researching three-dimensional printing of bone-like materials for orthopedic implants. In 2010, researchers from NASA asked if the research team might be able to print 3-D objects from moon rock. The idea is to limit how much material spaceships would have to carry to an off-planet outpost.

Whenever Phinn contributes to a thread it suddenly becomes a conversation stopper anyone else notice that ? LOL

Oh yea! Oh Yea! Well, I got news for you... (brb, for I need to Google up some news)  

The end result was a series of circular clear discs with colored centers, symbolizing the eight planets of the Solar System inside, and denominations ranging from 1 to 10.[1] Each quid coin would have its own unique code number, similar to the serial number on paper currency, to allow tracking, and to prevent counterfeiting. Travelex stated it planned to work with the Bank of England to begin registering the Quid as possible legal currency in the future.

New currency for space travellers
 
Quids are made from the polymer used in non-stick pans
Scientists have come up with a new currency designed to be used by inter-planetary travellers[sic].

It is called the Quasi Universal Intergalactic Denomination, or Quid.

This.

If we could incoorperate a shark somehow it would be the perfect internet.

Be sure the correct shark species is chosen, for we don't want any remoras hitching a ride.

Found something intellegent--AGAIN--to add to the conversation.  

http://en.wikipedia.org/wiki/Quasi_Universal_Intergalactic_Denomination
...

It costs way less to mine for water and materials in space, and transport those materials through zero gravity to the space station, than it does to mine for them on earth and launch them from here. The plan is to provide water and resources for the ISS to start with, and then space hotels and other space tourism venues once they become available.
So, it's mostly the gravity thing

Mars would end up playing a part for things we may need to process first, and a processing factory in space is too costly to build (building airtight caves on mars is cheaper than building large airtight can in space) or for things that we do need on earth that may be hard to get here (gold, plutonium, platinum, rare earth metals, etc.)