If you are developing to the peer to peer collaboration APIs you may see a tray icon appear when you first use the APIs. This is the collaboration host (the process name is p2phost.exe, and it is a user mode process). p2phost.exe is responsible for listening for incoming invitations, and for popping up UI asking the user to authorize the launch of an application. In addition, you would be able to opt in and out of people near me publication.