The likelyhood of happening to run into your friend's computer on Gnutella is very small. Gnutella does not use a central server. There is no database of files to search through. Instead you search only a few computers that you are connected to. Those hosts then relay your search. The searches are limited to a certian number of layers, which creates a network horizon, where you cannot see past. Unless you specifically connect to your friend's computer, you probably will not see them. You can do so by adding the IP of your friend's computer to your list of IPs, and hope Xolox picks the one you want. P2P is not the best way to download files that you from a specific host.