Project advice.

So I am a software engineering major, my capstone is quickly approaching, and I don't know what to do. Now the capstone is pretty open, I get to choose what the project is, what platform it will be on, and what language it will be in. Web sites are frowned upon so I am going to go in a different direction, and would like to use Java, and I normally do my development on Linux. Ideas would be very appreciated?