There's an ongoing series of blog posts by Judith Tarr, who wrote the e-book on Writing Horses: the Fine Art of Getting It Right, over on the TOR books website. This time the main thrust is what an alien society based on horses might look like. Makes for some fascinating reading, as she's been going on the topic for a few months now. What's more, the comment threads are just as interesting as the originating posts, which makes for a really nice treat in this day and age.

There are also some posts on other horse-related topics more geared towards fantasy writing and movies as well. I highly recommend any of her writings on the subject of horses, as well as her numerous novels.