Why don't you get involved in an open source project? That way you can work on something that interests you on your own schedule, and do as much or as litle as you have time for.
Sorry, I'm not native American. What's open source project means? Just build any applications I like? Or that will be some requirements and guidelines I can follow just like the SCJD assignment?
Sourceforge.net provides a good place for gaining software development experiences. But commercial java applications are relatively very small in numbers compared with PHP applications. You can consider to start a new project and transform those concepts in PHP applications into java struts application for example.