I'm not a skinner myself, but for those who are and use gimp the new version was released today. It is fully supported across Windows/Linux/ and Mac I believe and is supposed to be more "professional".
It is probably at least worth a look if you are using the 1.X line or are just on the lookout for a free peice of software to use for skinning.
Link below, but it has been slashdotted so it might be a while before the webserver recovers
http://www.gimp.org/
