The ports are ethernet network ports. You would normally use them to network your computer.
The Speedtouch is a USB modem, and connects to the USB post of your computer. It's not a hack, but needs the correct drivers (should be no problem on Win2k Pro) to work.
An alternative to the USB ADSL modem is a combined ADSL modem and router. This connects to the socket the same as the Speedtouch, but it will connect to your computer via a standard networking cable. Normally, you will configure this router via a Web interface to it, but you won't need special drivers. If you're using an Amiga, it would be more likely to work with the router than the Speedtouch, but in your case it won't matter.
A router is also better if you use more than one computer on a home network, and want to give everyone access to the net. Win2k can do this too (so you could do it with the Speedtouch as well) but it's not a great solution.
