What are some popular skills relevant in today's industry?

I have a couple summer projects I wanted to work on, and was wondering which one to do. One is a data analysis project focusing on learning R, Machine Learning, Big Data, and Statistical Methods. Another one is setting up my own selfstarter clone in node.js, with social sharing, and accepting Bitcoin payments (Stanfords Startup Engineering course), working with the Kinect, or building an ios app in Swift. Any advice? I'm kind of interested in the Startup Engineering project but I feel like the first project will give me more skills and experience.