Thanks very mcuh for your help guys, it is very much appreciated and helpful.
It is good also to see the debate a little more… civilised 
To clear things up a bit,
I am looking to run 2 sites, one called http://www.truebluecasinoguide.com and one called http://www.linuxonlinecasinoguide.com.
With both of these sites, I was hoping to to have the same content though I wanted to set it up as so that Titles and etc would reflect which site was typed in e.g. when I type in trueblue…, it would goto the trueblue… title, typing in linuxonline… would have the corresponding title linuxonline… as well.
My hope was that I would only have to update the one wordpress system and both would update at the same time. My concern was whether I would get penalised for duplicate content and, how I could achieve the desired outcome if it was worthwhile.
My webhost allows me to “forward” or “point” linuxonline… to trueblue… but I wasn’t happy with it only going that far I wanted to customise the content to each domain.
Carlo,
I think wordpress is great! There are so many plugins so it is really easy to get it to do something I want, to the extent that I have been able to edit the .php files and have a bit of a clue as to what I was doing (if there was a qualification for “Trial and Error” then I’d be the leading Subject Matter Expert ).
Thanks again for all the help sofar, I have learnt a great deal already.