Guys, I'm in my penultimate quarter of grad school and have a software engineering internship lined up at a big 5 tech company. I have dabbled a lot recently in Python and am average at Java. I want to prepare myself for coding interviews when I apply for new grad positions at the Big 5 tech companies when I graduate at the end of this year. Since I want to have a good shot at all 5 companies (Amazon,Google,Yahoo,Microsoft and Apple) - Should I focus my time and effort on mastering and improving my Java. Or is my time better spent checking out other languages and tools ( Attracted to RoR, Clojure, Git, C# ) I am planning to spend my spring break implementing all the common algorithms and Data structure out of my algorithms textbook in Java.