I have yum and rpm, and I really only how to install packages using these commands. When I tried to yum install figlet on a new CentOS6 virtual machine it couldn't find it in the mirrors list. I tried to localinstall a figlet package but it wasnt signed and yum wouldnt install it.
here you can download the figlet packge and install it with rpm -U, or do yum --nogpgcheck packgename .
as a general recommendation, i am encourge you to add the RpmForge repos to you centos installation, since it includes a lot of programs.
see this answer.