Ye' old general discussion board. Basically, for everything that isn't covered elsewhere. Come here to shoot the breeze, shoot your mouth off, or whatever suits your fancy. This forum is not for asking programming related questions.
You could try looking at various photo gallery applications. Many have user comment systems. You could also look at blogging software apps. Or you could sit down with pen and paper and write out some logic for your own system.
I would recommend coding something simple yourself - most gallery packages are overkill and what you're doing will likely be fairly straightforward.
That way you'll get extra brownie points with the teacher, AND you'll have something to show people when you're job-hunting. Experience is way better than just a diploma/degree/whatever when it comes to interviews.