Despite the current rise in popularity in books distributed electronically, there seems to be an almost complete lack of tools to create publications for these eBook readers. InDesign has some tools available, but it still seems that you’ll want to “break in” to the ePub (or Mobi file for that matter it seems) and edit away HTML and CSS. Fun.
It occurs to me, that a carefully constructed web page has a better chance of being converted to either of these formats than an InDesign file. I may need to dust off my old PDF to HTML conversion notes and see what I can dream up…