Right I got Fable 2 recently and I already own every property in the game cus of this.
Basically the game lets you earn money on houses you rent out wether your playing or not. Buy up as many properties as you can and save the game then dashboard out and set the clock as far forward as you can. Then when you log back into the game you should earn quite a large amount of coinage! Remember you need to be disconnected from xbox live to do this as it will automatically attempt to set the correct time.
Repeat until you have everything basically!
Credit goes to www.gamefaqs.com.
Its a pretty good site, the Uk board is a laugh too so check it out!