I've had pretty good luck with UVMapper Classic; I model in Lightwave, and as was suggested above, I break my models up, export a part and map it, then re-import it into Lightwave. When I;m done, I have several layers in my UV maps, but they are logical and relatively distortion-free, something I find much harder to do when the entire model is mapped at one time. Of course, this works much better for mechanical models than organics, since machines and non-organic objects can be more easily broken into components.