Soulrider is right joopson.
I had a site where i got my one from ill see if i can find it, try googling chrome spheres or somthing.

And you need a camera that you can change the apature with, but basically you need to take pictures of the chrome ball (they come with a screw hole so you can use a tripod with them), around 8-15 then crompress that into a floating image format in hdrshop or photoshop, You can then change it into an angular map or whatever you want to use it for.

The method joopson is describing is another way to go about doing it however by taking multiple images at different exposures you are taking advantage of the floating format data range as it is designed for. Making the output sharper and more detailed for refelections as well as lighting.