As these two posts illustrate, you don't need to immediatly leave your comfort zone in order to use one of the more interesting topics to take hold of the software industry in the form of Concurrency.
Jacob Hookom post explores a series of constructs avaialable in Java 5 designed to deal with concurrency issues. In addition, Torbjörn Gannholm post provides a follow up inspired by Jacob's post on the topic.
Read Jacob's post 'Accelerating Applications with Java 5 Concurrency':
Read Tobe's post 'Using Java concurrency utilities':