As a studying Electrical Engineer, what project should I do during winter break?

I am currently studying Electrical Engineering. Everything I am learning is extremely interesting to me. Winter break is coming up, and I want to make use of the month I have off.

- I am pretty good with Java and C++. Not great, but good. Should I try to elaborate on one of those for a month?

- I am currently in a microcontrollers class, and loving it. We are using Assembly to program the PIC18. I would love to make something awesome with a microcontroller, but am not sure I have enough knowledge at this point to do so. Would this be something I should look into?

- I have always been interested in hacking. Would it be worth spending a month just reading/learning different things about hacking? What languages should I look at? What should I read? What should I do to learn?

Programming, microcontrollers, and hacking are probably my best options at this point. What do you guys recommend? Why? Which is the most fun to you?

This is exactly what I was looking for. I have heard of both arduino, and raspberry pi, but I believe this is where my knowledge is lacking. What are their capabilities? Obviously I will look into them now, but what can they do? All I have done in my microcontrollers class is make an LED screen say different things, and move wheels forward and backward. Is this what these two do?