Ok. I'm lazy so I thought I'd try to do it with particles. The trouble is
that elements within a particle group orient to camera en masse so if you pass a camera through the middle of them the individual particles do not rotate to point at the camera.
Gah!
Looks like I'll have to build it by hand (Or not turn the camera

There are probably some really technical reasons why this cant be done but I'd thought I'd ask anyway.