Replace one Texture in a linked object

Not sure if this has been suggested before and I'm sure it can be done with LSL, but would be a handy thing to have in the interface. If someone's got the LSL to do this, please drop it on me. I'll probably end up writing it soon.

Say you've got a linked object with 20 or so prims and maybe half a dozen textures in it. You decide that one of the textures isn't quite right. And you want to play with different textures to see what's best. Would be so nice if you could scroll through the textures in the linked object and drop a new one on top to replace *only* that one texture. Instead of having to select all the faces that have the texture.