I know they had cool shirts when POA came out. My best friend got an awesome jail like shirt that says Azkaban on one side and Sirius Black on the other.
Also, I saw this on Mugglenet.com earlier as well
Matthew Lewis in the MuggleNet chat
Harry Potter actor Matt Lewis (Neville Longbottom) will be live on our chat network on August 25th at 3pm BST / 10am EDT / 9am CDT to answer your questions.
Please e-mail your question suggestions to webchat-questions at chat dot mugglenet dot com and include your name and location. We'll pick the best 20 or so and pose them to Matt on the day.