I think I know what you're saying , Vlad, but wrap deformers are very processor and memory intensive. I might try the muscle system included on the rigging disc from the Hyper-Real DVD set that Alias has available. This muscle system doesn't calculate the entire mesh. From what I remember from the DVD, it only calculated the affected vertices via a weight map that you paint. This way, you can use a "muscle" to deform an area of skin without having to deal with the rest of the skin being calculated.