http://www.arborarts.com/

Do you have an upcoming family-event? Anniversary, wedding, childs baptism or maybe a family reunion? Maybe you just want to put your genealogy work up on the wall? This might be something to look into!

I have not tried them, but their work looks really beautiful.

From their homepage:
They create fine art family trees customized with the provided family history. They say they use the finest art reproduction techniques available today: heavy watercolor paper, giclee printing with inks designed to resist fading for 200 years, beautifully matted with archival materials and framed with your choice of framing style. Your family history combined with a beautiful design and created with the finest materials results in your very own personalized work of art.

They can make descendant trees, showing the growth of your family. It displays a couple, along with their children, grandchildren and great grandchildren. Or they can make an ancestor tree, that shares the history of your family. It features a couple, their parents, grandparents and great-grandparents. It also shows the children of the couple.

Examples: