Comment Salamanders Do It (Score 1) 88
Scientific American did a good piece of limb regeneration back in April 2008(Regrowing Limbs: Can People Regenerate Body Parts? Preview - http://www.scientificamerican.com/article.cfm?id=regrowing-human-limbs)
Key points are that salamanders are best at complete limb regeneration but humans (and many other animals) scar instead of regenerating. However, if we turn off the scar system and prime the regeneration system, we may be able to regenerate whole limbs, too. One of the neat points made in the article is that salamanders cells seem to know how to re-build the lost limb with first growing a "baby" version. In other words, lose your limb and an "adult" one will regenerate without you having to wait 15 years for it to grow to the right size.