If your only coding experience is 8 weeks in a summer course, then don't bother trying to show off to potential employers. You're too new to make anything decent unless you put a LOT of work into it. I don't mean 5 hours a week, I mean 5 hours a day if you're trying to get it done this year. If you want to show it to potential employers, your best bet is an android application. Publish it to the market and whip out your phone during an interview to explain what you've done. It won't be very good, but at least it'll show initiative.
http://developer.android.com/index.htmlIf you just want to improve coding skills, my recommendation is to google for more java courses online and look at their homework assignments. And read books.