This year there are several formats available:
- PDF with one column, for your on- (or off-) line reading pleasure
- PDF with two columns, for better printing, in both 8.5x11 and A4 page sizes
As for those last two... I'm still figuring out Calibre, and I didn't have time to look at all the files, so it's quite possible they're not going to be perfect. We're pretty much shooting for readable at this point. If you download either of those and have suggestions for improvement, please let me know--I can upload new versions easily enough if it's worth it, and I'd love to do things better next round. Right now, though, I want to get them out there.
And if you'd like an e-book format other than .mobi or .epub, please comment here and let us know why. I think those two formats cover pretty much all e-readers, but it's possible I'm missing something, given how ridiculously complicated the whole subject is.