It's shameless self-promotion, but my startup Leanpub (http://leanpub.com) lets you write in HTML or Markdown, embed external code samples, save your files in Dropbox and produce PDF, EPUB and MOBI with one click. We sell all 3 formats, with automatic update distribution to existing readers when you publish a new version (so you can sell your book while it's in progress). You keep the rights to your book, etc.

Uh... That's actually awesome. I'll start writing a book now, and that's where I'll publish it.

Great! Let me know how it's going, and if there's anything you need us to improve...

I definitely will! Right now I just wish you supported LaTeX, though.

That sounds super cool. I'm gonna check it out.

Game on, my friend.

What to say when comment upvote counts are gone. Can't upvote this enough. (For me, mobi prefered.)

Me as well. And pdfs tend to look/read very poorly on a Kindle (especially if they contain code blocks).

+1 .mobi for kindle

avdi: let me know if you'd like any help packing a .mobi, I'm working on a quick-tutorial post.

As I replied above, I'll probably work on Epub first because that's the format I got the most requests for when I did a survey. But after that I'd be happy to get some Mobi pointers. Email me!

I'm gathering feedback on which format to work on next. So far the most-requested has been .epub.

If you do go the epub route, let me know know if you're interested in trying eBookBurn.com (my startup's site), and I can issue you a promo code.

You'll also get a .mobi version simultaneously.

Yes, please.

FWIW we (getdpd.com) totally agree and are working on adding this feature to our system soon. Vendors will be able to upload the file variants themselves or we will do the conversion on the backend.

As I'm usingn DPD for this book, I'm happy to hear that!

P.S. Would you mind getting in touch with me? I have a script to share with you guys.