Tailcast

Tailcast is a website made for artists, writers, and musicians.
It allows people to share their pieces for free or for sale, and it gives them a place to form community with each other. It allows for drawings, paintings, sculptures, photos, and other artistic mediums; for poetry, short stories, and passing thoughts; and for musical works in progress or full compositions.
It creates a space open to collaboration by allowing people to leave comments on other people's posts. Each post is put on the website itself, and each member has a page to themselves, where they can share things about themselves and have conversations with other members.

Essentially, it's a combination of Facebook and Deviantart.
But it works well. It's small enough that nothing has gotten out of hand, but it's large enough that it has a good flow of artists. And its friendly, clean, bright layout makes it a happy, trendy place for people to visit. I think that Tailcast will do very well in the webworld, at least well enough for its creators to make a decent profit.