Ok, so there are clearly a few mad scientists out there when stuff like this comes up:
Wired: Military Seeks Invisibility Cloak
Or for those of you who have access to the journal Science:
Science 26 May 2006: 1120
Here's a quote from the Wired news article:
"Is it science fiction? Well, it's theory and that already is not science fiction. It's theoretically possible to do all these Harry Potter things, but what's standing in the way is our engineering capabilities," said John Pendry, a physicist at the Imperial College London.
Maybe it's just my "experimentalist" point of view... but just because a material theoretically could do something doesn't mean that material can exist? Sure, I suppose it might be possible, but as far as I'm concerned they are leaving the hard part up to someone else.