There are ceilings and then there are ceilings with exposed beams. It's like being born with perfect eyebrows. You don't always notice them at first, but then you realize they make the face, or in this case, the living room.
Wood beams are beautiful in their natural, knotted state, or you can paint them for a bold dose of color. And look at the amazing job someone did painting between the beams in the 4th photo.
There are even companies like Faux Wood Beams which can can install beams in a range of styles. Kind of like drawing on your own eyebrows.
(Images: 1 with permission from Flickr member house dreams; 2 Accent Home & Garden; 3 Alicia B. Designs; 4 Nikdaum; 5 Atticmag; 6 Cote de Texas; 7 Guidebook.SE; 8 Harmonious Palette; 9 eHow; 10 Country Living)