Here's a sneak preview of how 0.7.5 uses special periodical formatting for iPad.
If you download recipes with Preferences|General|Preferred output format
set to EPUB, and Preferences|Conversion|Page Setup|Output profile
set to iPad, calibre will do some special formatting for the touchscreen.
The section index of a downloaded recipe is shown below on the left page, with each section title a clickable link. The right page shows the first section, with each article title a clickable link.
Each section has a navbar providing navigation to the previous section, the section index, and the next section.
Each article has a navbar providing navigation to the previous article, the article list for this section, the section index, and the next article.
If the recipe specifies a cover, it is shown in the iBooks Table of Contents. You can also see the cover by dragging the slider at the bottom of the screen to page 1.
Some people will ask "why bother downloading periodical content when you can simply read it online or use Instapaper?"
My preference is to have the entire periodical available offline. That allows me to read it at my leisure or in conditions where connectivity is not available. Instapaper is great when you come across a site you want to read later, but with periodicals I prefer the serendipity of paging through the content, deciding what I want to read as I go. Also, I like having access to the iBooks dictionary while I'm reading the news.