I'm downloading it now. First beta == interesting curiosity, but nothing I plan on using on a regular basis. Still, I saw a demo of the Firefox 3 beta a couple weeks ago at the Web 2.0 Expo in Berlin, and it was amazing -- particularly the zoom-whole-page feature that lets you resize all the elements on a page, up or down, including images and form elements. No more squinting at tiny webcomic writing! No more tedious side-scrolling for huge-mongoose inline images! Link (Thanks, Al!)
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.