What is the biggest P2P network and most download P2P application ?
It is Skype !
But how can you donwload skype in their website ?
By http, only... There is no P2P options :-(

According to this post on Skype Blog : http://share.skype.com/sites/en/2005/11/200_million_downloads.html
Skype use a 500 Mbit/sec line to deliver their small (9,8Mo) application. It is pretty amazing when you know the founders of Skype are also the founders of Kazaa (used to download billions of files with P2P).

Here is a P2P link on our platform to download Skype with P2P :
http://www.peerfactor.fr/getdownload.jsp?ID=1202

Actually, with Skype you expect a similar download option on their website (certainly developped by them) or at least an auto-update P2P function within Skype.