I've got an iMac with system 9.2, an ethernet connection, no firewalls, and somehow I still can't get Limewire to connect. By the way, what the heck's an ISP, and if I need it, how do I get it?

ISP=Internet Service Provider, the one who is paid to allow you connect to the internet.

If you are in a university or workplace, the Network Administrator makes the arrangements to pay for the connections, but might also control what kinds of connections you make. Some universities, for example, block connections to the Gnutella (the one LimeWire uses) or other filesharing networks.

If you can find others who connect to filesharing networks on your ethernet, perhaps they'll have suggestions.