Mobicents team has mavenized all their code including Mobicents SLEE Server, Sip Servlet Server, Media Server, XDM Server and all the examples. This could be a bit painful for users who are deep into ant and never looked at maven before. However once you start using it you will realize the power of maven and will understand the principle of maven of managing a project's build, reporting, doccumentation from a central piece of information known as pom.xml
For beginners look at link http://maven.apache.org/users/index.html
I have briefly looked at book Better Builds with Maven and can recommend for starters.