Today is the day to celebrate all things Tolkien!
September 22nd is Bilbo and Frodo Baggins' birthday. Well, sort of. Hard core Tolkien fans will tell you that the Middle Earth calendar is slightly askew from our own count of the days. Nevertheless, this is considered Tolkien week, so be sure to pop in your LOTR DVD's or crack open some Tolkien-authored literature.
If you recall, THE FELLOWSHIP OF THE RING opened with the Shire celebrating Bilbo's birthday.
So if you want to plan a party, anything with ale, dancing, food, tents and fireworks seems appropriate. You may even find some interesting Tolkien events going on near you! Check your local papers.