Team Niall has added a bunch of really great designs to the charity shop for Niall's charity drive for Autism Assistance Dogs Ireland. You can check them out here:
You can also donate directly to the charity at http://www.justgiving.com/niall22
And follow the Niall charity drive tumblr for all Niall charity news!
Edited to add: Some of the designs had to be redesigned due to US Spreadshirt restrictions, but are still available in the UK store.