Kenneth Oppel's website was one of the first I recall to use elaborate mini videos about his books. I remember the first time I saw the Airborn site it took my breath away. Can't wait for the next Matt Cruse book, Starclimber.
“When you’re writing a book, you’re certainly not sitting there thinking, ‘And wait till they see the Web site!’ ” Larsen said. “But it does offer a great opportunity to experiment with delivering character and narrative across different mediums.”
Dav Pilkey offers a raft of rather terrifying music videos on his site in English and Japanese including: Super Diaper Baby Country Shuffle, Calling Captain Underpants!, and Go Poopypants!
The "documentary" about the making of the videos, Behind The Waistband explains the origin of the videos.
Newly minted Newbery winner, Neil Gaiman, reads The Graveyard Book, via video, in its entirety, on his Mr. Bobo's Remarkable Mouse Circus website. Authors are not always the best presenters of their work but that is not the case here. Gaiman's reading is pitch perfect (which is probably why he reads the story in the audiobook version too. )
Meg Cabot has a YouTube video presence to promote her books. I think her interpretation of literary and movie classics using her Madame Alexander and Barbie dolls are my favorites.
John Green's heroic Brotherhood 2.0 project spawned the entire Nerdfighters movement via VlogBrothers. Thinking of John Green, reminds me of Maureen Johnson's very funny videos.
With websites to watch, blogs to maintain and now video projects, it is a wonder that authors get any writing gets done at all.
What are some other children's / YA authors using video to publicize their work and interact with readers?