I'm happy to try e-books and I desperately want to add an iPad to my gadget collection, but I think I'll always prefer paper books, if for no other reason than to get a break after staring at some kind of glowing rectangle all day. But aside from the occasional impulse buy of The New Yorker, I do all my periodical reading online, either on my iPhone or in front of a proper computer.
Reading online doesn't mean you have to trade quality, feature-length writing for short blog posts either. Sites like Longform.org curate the gems of long-form journalism from suggestions by readers (Jack Shafer has a nice profile of its founders at Slate), and Long Reads performs a similar service on Twitter. Combine those with my favorite site, Instapaper, which compiles its own list of hits called Give Me Something to Read, and I'm never at a loss for reading material, even when I forget to bring a book.