The Ultimate Jam 2012 has a special shop called “Merch” . Here you can buy Ultimate Jam related items and the catalog has even 3 hidden items. Here’s how to find the shop and the hidden items:
Use your map to go the Snow Forts. Once you are there, click on the smaller building in lower right. The first page of the Merch catalog will open.
On the first page, to find the first hidden item, click on the fourth light (left to right) from the bottom of the page.
To go to the second page, click on the arrow in lower right. Now click on the sixth light (left to right) from the bottom of the page.
Have fun with your new items from the Merch.