Millennium (with 2 n's) comes from the Latin words mille meaning a thousand and annus meaning years, so it means "a thousand years". So I suppose millenium (with 1 n) comes from mille and anus so it means "a thousand arseholes"! That is exactly what was in the Millenium Dome!
The first zone I went in I was out of within a minute (probably because it was money and I didn't Spend a Million!)