A 10 watt, 3kV piezo-transformer not much bigger than a ballpoint pen.
http://cds.linear.com/docs/Application%20Note/an81f.pdf
From the excellent Reading Jim Williams blog.
After seeing this, I can't believe we're still using magnetic core transformers. I realize they're good for high-current, low-frequency applications. But this is so much better for LCD backlights, I can't believe it hasn't come to utterly dominate the marketplace.
This is probably how the people that invented fuel injection way back in the 1920's felt. "Why isn't everyone using this??" :P