Ask HN: Transitioning to the security field?

Hey everybody,

I'm finishing up my undergrad in computer science with a specialty in systems and network security. I've had a co-op doing development(Java, some SQL stuff) and have worked in IT and tech support.

I'm familiar with a lot of security tools in the sense that I've used them in labs, frequent the forums, and can manage my way through man pages; but I don't have any real practical experience with them.

Aside from taking a C|EH, CISSP, or CISA certification(very expensive for a college student) what are some things you would recommend to help me get my foot in the door so that once I graduate I can more easily get a job doing pen testing, information auditing, etc?

Thanks in advance.