From the announcement:
Let the Pre-Registration Begin!
Special Pre-Registration will include a black t-shirt and a pair of Gnome dice.
To Pre-Register: pick your T-Shirt size, hit the PayPal button and fill in the relevant information.
You can choose to Pre-Register for GnomeCon admission only (no shirt or dice) for $30
Kids under 12 are Free with a paid Registration. (please include their names in the badge name box)
You will be able to change quantities or continue shopping from the PayPal page, if you are signing up for more that 1 person.