Oktoberfest is an important part of Bavarian culture. On October 12th 1810, Crown Prince Ludwig was married to Princess Therese of Saxe-Hildburghausen. Royal festivities were held and the citizens of Munich Germany were invited to attend the 16 day celebration, including games, traditional foods, as well as the horse races at the close of the event.
Beer steins are available all year at Zazzle, you can find many pre-designs or create your own designs. Look at any mug design listing, and you will see the options to pick stein instead of normal coffee mug. Or get both matching coffee mug and other service pieces to add to your set!
(read more about Octoberfest here at Wikipedia)