where are the pictures of the skype contacts saved (see if someone is invisible) i just thought you could see if someone is invisible in skype, if you just delete (reset) his profile picture. Because i know if you install skype on a new device the profile pictures are saved only if he is online (or invisible). That means if i just want to so if someone is invisible you just delete or reset his profile picture and if you see after a few seconds his picture again = he is invisible.

BUT...
i don't know where the contact picture are saved on on my mac (running mountain lion). I just couldn't find theme...
so if you know where they are saved, would it be great.
On Skype 6.3.xx the avatars are stored in

~/Library/Caches/com.skype.skype/(your skype name)/SKAvatarCache


in TIFF format. You can view them by in Preview by opening Terminal and running 

open ~/Library/Caches/com.skype.skype/(your skype name)/SKAvatarCache/(name of the file)