I've done a little tiny bit of work with mapping using the various incarnations of the Unreal Editor. I've done more with skinning, and I started to progress pass the generic 'color edits' everyone starts off with, but I've stopped. I also got involved with an interesting mod for UT2004 called HaloUT - I was going to UV map a hoverboard sort of thing, but the whole mod sort of lost it's pace.