Its the largest element currently known.
Until its officialy named, I think its still ununpentium (i.e. 115, its number in the periodic table)
As such a large element, its very very unstable and as far a I know, hasn't existed for more than a few fractions of a second, and even then that's only under laboratory conditions.
Is that all? I thought they would have got further than that by now!
Wayne, dunno if its icky, but its so radioactive that if it was available in any sort of quantity it'd probably have a nice green glow.