It's not well known, but Rhino 4 already has an excellent utility for converting image maps from one projection to another. For example, inputting a sphere map and outputting a horizontal or vertical cross map :

1. install the RDK plugin from the Labs wiki page
2. in the RDK's Texture Pallete, create a new "Projection Texture Changer"
3. assign your sphere map to the bitmap input
4. set the input projection to "lightprobe"
5. set the output projection to your choice of output (rectangular, h-cross, v-cross, etc)
6. Save as Image

Might be a handy tool for Rhino/MoI users, once MoI uses reflection maps...

jonah