@weeeman:
if your main campus firewall or resnet firewall has the BT ports blocked, you will not be able to get any incoming connections. this problem can be easily resolved by changing your BT client to accept connections on ports that are open.
if your campus or resnet firewall is running a packet watcher (i.e. packet shaper), then you might be in a little bit of trouble. such a program watches all incoming traffic and either blocks it or let it through, depending on what type it is. BT might be blocked at that end. even if it is not blocked, it might be allocated a very tiny % of campus bandwidth, so even if you are able to download, it will be ultra slow. that is what our campus decided to do to kazza packets. we gave it a total of like 1% bandwidth shared among all the students... it was slooow. you must talk to your sysadmin to change these things
if what you're connected to does not give you an external IP, then you will have the same problem as the router users, with the incoming connection not knowing which internal computer to send the packet to. in this case, you will have to tell your sysadmin to forward the BT ports to you, but i doubt he would do that
good luck!
@all:
please correct me if i am wrong with any of these comments. i am unfamiliar with other networking strategies that some colleges might offer