Yeah Morgwen, important feature!
Choosing another port then 6346 is a great feature of Gnutella, it is much harder to get blocked if many do. Actually, I run my Gnutella on port 443 and/or 563, this allows ppl behind a SOCKS or especially behind a HTTP proxy (e.g. a simple 'squid') to download files from me. Well explanation is tricky, the squid default configuration of Linux distributions allows to tunnel connections to this destination ports.

acl SSL_ports port 443 563
http_access deny CONNECT !SSL_ports

So, if an official host on your university runs a squid, you're fine and could download from me (assuming your Gnutella client has a buildin HTTP1.1 proxy support, Godxblue add this to the TODO list plz). Think geek!

Greets, Moak