3000 gold a day
Go to Alcarya of white haven's fine alchemist in balmora and bribe her until she is your friend, then go to barter and buy diamonds off her (she automatically restocks the amount you buy off her) for about 15-20% less than they are worth.
Next sell them back to her for 15-20% more than they are worth. Continue until she runs out of cash (she has 3000 cash) then go away and sleep until the next day, then go back and repeat.
I think this is a great cheat for using at the start of the game as I went from level 2 to level 19 in about half an hour of doing this and spending it on training.
Added by: Zyplof Jan 9th 2007, ID#6839