I use this in a creature steal deck. It works great for activation costs for creatures that I've stolen. Nothing like pay 1 regenerate. And it's not even all that terrible when I don't need my opponents colors because it doesn't come into play tapped. At least I have an (effectively) colorless mana.
Plus, when someone plays their city of brass or whatever, I get all five colors too.
-- By Thomas Stone from Tampa, FL on May 07, 2010
In a 5 color deck this land is perfect. In multi-player game that land is really cool. I drop it first turn i got already my 5 color with it :)