In the host catcher you'll find ip adresses that run a gnutella servent.
Your servent got them from either a hostcache (a auto connect host) or from another servent you was connected to.
Becouse the Gnutella network does not work with a central server, Phex needs those adresses to connect to the network.
All gnutella programmes are server and client (servent) at the same time .
If you want to learn more about gnutella, read
this