I'm not sure how Kazaa works in regards to servers, but the most effective way to get around such a restriction is with what is known as a proxy server.
There are several ways to block access to internet services. The most common is for the administrator to block access the IP address or even IP block. For example, if Kazaa's central server was located at 192.168.92.5 your school could block all access to either that address, or even on that IP block (192.168.92.1 to 192.168.92.255).
The way around this is to find what is known as a proxy server. Instead of connecting directly to the Kazaa server, you connect to a different server that someone outside of your university's domain has set up for that purpose, it then acts as a go-between, forwarding your requests to Kazaa, then relaying those back to you. The problem becomes, when a lot of people from inside start using the proxy server, the school eventually catches on again (hmmm, 95% of our bandwidth goes to this one address, why is that?) and will eventually block that address too.
Look around the internet for discussion boards devoted to Kazaa and p2p networking, you'll have better luck there, and will often be able to find a list of servers to use.
Happy contrails - I support B747Skipper and Jetguy