On our LAN parties at the time, everyone started to use Trillian because of their support for the Bonjour protocol which used multicast DNS locally. That way you could easily "group teams" together, because the hostnames / IPs were also visible and you could add them then to the Hamachi groups where the games happened.

Hamachi was an amazing tool before they got bought, it made networking so easy for everyone; and you didn't even need to know what an IP was.