I discovered an excellent web magazine covering modern web development in TreehouseMagazine. What really struck me was how they've used basic Acrobat PDF to present their core product - essentially a magazine.

Normally, many newsletters are designed in portrait mode on 8½ x 11. Shifting to landscape mode however, yields huge gains in viewability and usability, especially for publications geared to be read from a website.

Even at 125% magnification, landscape shows nearly all of a standard page. This changes the overall experience for the reader and makes reading more enjoyable.

A couple of factors are driving this. With high resolution monitor settings getting to be the norm (1024x768 and higher), landscape mode performs beautifully even at 125% magnification. Almost 95% of the page is in view at this range. What's more, is that you gain a sense that you're not missing much. This changes the experience of reading the publication. It's more enjoyable to consume.

The only drawback I can find relative to this option is for publications that are cross-purposed. (Meaning the print version is put online for download or vice versa.) Readers might fret over this when a hard copy is generated. Either way, a standard 8x11 fits the bill.

If you are publishing an type of publication that will be distributed or experienced electronically, conisider this format as a very strong option.