The team at Scribd, a popular site for sharing written content, says it wants users to access that content even if they’re not at their computer.

As one step in that direction, the San Francisco company announced a feature in February that allows users to read Scribd documents and e-books on a range of smartphones and e-book readers. Today it’s extending that into the printing of physical books, by announcing partnerships with three print-on-demand services: HP’s MagCloud, Blurb, and Mimeo.

Chief Technology Officer Jared Friedman said many users already print out at least a few pages of a Scribd document for reading, so it made sense to add more serious support around that. Instead of just printing something out at home or in the office, users can transform the electronic document, magazine, or book that they’re reading on Scribd into a high-quality printed equivalent that’s delivered in the next day or so.

Readers won’t just be able to print out every document on Scribd, added Michelle Laird, director of communications. From the business side, this is about enabling publishers on Scribd to to sell physical copies alongside the electronic version, perhaps as part of a package combining both — so publishers have the option to enable or disable print-on-demand.

With high-profile authors, publishers, success stories, and now with the ability to sell physical copies, Scribd has built up an impressive e-book store that, if not exactly an Amazon killer, is looking more and more like a viable alternative. Each of the three print-on-demand companies has its own specialty, with MagCloud doing magazines, Blurb doing books, and Mimeo doing business documents, and there are plans to add more partners in the future, Laird said.

“We were confronted with this interesting challenge because the content on Scribd is extremely broad, from PowerPoint to short stories to full-length books to sheet music,” Friedman said. “There was no print on demand company that had tried to tackle such a broad swath of content types at the same time. We ended partnering the combination of those three to print the full breadth of content.”

Laird also sent me a few stats about the early uptake of Scribd’s recently released mobile features. More than 100,000 people have used the feature, she said, with smartphones being more popular than e-readers. Among the e-readers, Amazon’s Kindle is the most popular, with the iPhone being the most popular device of all.