How Skype Works : WylieMac
not a direct quote as above but the link says
"...A very interesting moment about the Skype network is that it 'self-modifiable'. If you have the application installed, your computer may turn into a Super Node, without you even knowing it, because those capabilities don't have a noticeable impact on a computer's performance. SNs basically store the addresses of up to several hundred Skype users, without carrying any voice, text or file-transfer data. In that manner, the more Skype users come online, the more super nodes become available to expand the capacity of the network...."
looks like time to un-install skype..lol