I'm currently trying to hire an entry-level developer. There a lot of little things that separate school work from on the job work. Pick your favorite language and do a bunch of detailed research on the challenges corporate developers face. Speaking from a Java perspective, how are big projects built (Maven, Ant, Cruise Control, etc.), how are dependencies handled using those tools? How is automated testing handled (JUnit, Selenium, etc.) ? What other libraries are typically used? (Spring, Hibernate, Struts, etc. etc) You don't need to be an expert in all this stuff, but learn the basics and be able to describe what you've done with these tools, what you liked about them, disliked about them, pros and cons etc.

I think even a couple weeks of researching and using these tools would put you well above your peers the next time you go to an interview. In the interview, ask good questions: "How do you handle automated testing?" "Oh, you're using Hibernate, do you use it's query language?" Questions like this can demonstrate you understand (at least to some degree) the tools they are using.

Good luck.