I don't know how likely this is, but can we arm twist / beg / plead / bribe TGC to add a cubemapping capability?
Maybe the skybox functions have some nice internals which could be extended to do this?
I started off wanting to set shadows from scene lighting, but it would offer a bunch of other sweet capabilities if we had this.
From a different coversation with Janbo:
Convince Paul to implement something like SetObjectMeshCubeMap(ObjectID,MeshID,CubeImageID,CubeSideID,StageID) and I'll make you glass shader where you can set the reflectivity and refraction value