what about a cool mural on that wall

Woods wallpaper by Cole And Son would definitely accent the height of that wall: [houzz=]

Oh that wallpaper is gorgeous olldbobbi! Subtle but would make a great impact!

A mural would be fun, I'll have to see if there's big wall decals or murals, or maybe I could paint something! And the wallpaper is very pretty, but would it be too busy for a big wall? Just in the sense that the little trees are all close to each other.

To draw attention upwards you need a piece with multi-focal points instead of a consistent pattern in my opinion. A nice piece of art to tie in with your colors would do it!

You could do something like this out of drywall then paint it to match the wall, built-in-sculpture!
http://www.allanwexlerstudio.com/projects/wall-i-want-become-architecture

Bonjour, Wallpaper is calling for that wall. Have a look at library wallpaper. Have fun

www.muralsyourway.com is a great website

I think that wallpaper is anything but busy, to me it's very calming and with the vertical trees, it will draw your eye up. Lovely and serene.

Another option to consider are wall panels. Each of our wall panels covers 32 square feet and are available in seven embossed designs ranging from traditional, turn-of-the-century stampings to modern diamond-plate, ribbed and quilted patterns. You can check them out here: http://backsplashideas.com/4x8-wall-panels
Have fun with your project!

I think the Woods wallpaper depends on whatever else you have going on in your room. With a wood panel ceiling, it looks very busy (first pic). But with a minimalist room, it's very flattering (second pic).
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Large peel and stick wall decals for any style are available.

You could do a collection of pictures or photos in different sized frames or a collection of mirrors works well too

I agree olldbobbi, I really don't like it with the wood ceiling, to many lines. But the second picture is stunning.

I agree that art or photography would be the perfect thing to use. But, it depends on what is visually pleasing to you. It should be something or somethings that are uplift your mood when you walk in the room. A collection of photography in one theme could be an answer such as Paris, Venice, Coastal, flowers. Or a large canvas or mounted print. Etsy.com is a collection of shops and Etsy has a lot of unique items instead of drab items like you will find in big box stores. Most of the shop owners can customize their items - I know I can and my shop is nancyhehmann. Or just double click on the name in the left hand part of this response.

If you want art that might increase in value, go to Park West Galleries. They handle a lot of artists that are well known and have various styles and price ranges. I like Peter Max because he is an American icon. Google him and artwork from the late 60's to present comes up. He also helped restore the Statue of Liberty and according to his biography painted the firefighters who died in 911 and gave the works to their relatives.

Another item that might be good in a large are would be a metal sculpture and you can just input that in Google. I have even seen one person mount a metal gate on a large wall such as yours.

I feel like whichever approach you employ, the most important thing to consider is scale. Big wall means BIG whatever... Average scale art will be dwarfed on a wall of this expanse.

A wall mural or large size decal would be probably a great alternative to decorate the space. Here are some suggestions.