This long article of eweek.com tells about what every developer feels once he graduated, in my case I was lucky since I was developing for a time in the school in other projects larger than school projects. I totally agree with the article in this part:
Scherlis said the onslaught of open source technology has been a big benefit to students, as they are able to bet access to source code more easily and get students up and familiar with technology they are bound to see after graduation.
Byron Sebastian, CEO of SourceLabs, in Seattle, said many less experienced developers can learn necessary workplace skills by actively working on open-source projects in their free time.
Enrolling into an open source project (or checking and altering the code for testing purposes) will help you a lot to get skills in programming.