If you never need to read peer-reviewed or other academic articles, then this product will be of little interest to you. If you do, it will rock your world. Papers, which is basically "iTunes for your PDFs," has been around for a couple of years. It's a powerful, remarkable, and delightful program.

More recently, indie developer Mekentosj released Papers for iPhone and iPod touch, the portable kid brother of Papers for Mac. Where the desktop app is baldly powerful, the mobile app is precociously useful. It coaxes plenty of functionality from the iPhone OS, and it deserves high praise.

Papers stores your literature library on your iPhone. You can sort by Date, Title, and Rating.

Essentially, Papers for iPhone lets you take your entire research library on the go. In theory, it also lets you add to your research library, but I found that functionality to be less practical.

Papers for iPhone's notable features include:

• Sync with your Papers for Mac library using a Bonjour Wi-Fi connection. This worked flawlessly on my home network, but it failed when I was on campus, probably due to their byzantine network configuration. There's a workaround -- a computer-to-computer network -- but it's enough of a hassle that I'd only use it in a pinch.
• Search PubMed, Web of Science, Google Scholar, and other repositories to import bibliographic references. When you navigate to the PDF of a paper, it will automatically download it and associate it with its bibliographic metadata. This functionality worked beautifully on campus. Of campus, Papers for iPhone has support for proxy servers, but constantly entering my login info was enough of a hassle that, again, I'd only use it in a pinch. (I doubt this is Papers's fault -- more likely the University or the cookie-phobic Safari for iPhone is to blame here.)
• View PDFs. Papers for iPhone has a great, intuitive PDF viewer that makes the most out of the iPhone's small screen.
• Build and organize collections -- think iTunes playlists -- of papers, either by drag-and-drop (useful for background research during paper, thesis, or grant writing). Unfortunately, you can't create auto-collections (like iTunes's Smart Playlists) on Papers for iPhone. (You can on Papers for Mac.)

You can review and edit the bibliographic metadata for your papers.

Papers for iPhone can function as a stand-alone application, but I don't recommend purchasing it if you don't already own the desktop client. I can't imagine it's worth your $15. Papers for Mac also comes with a 30-day free trial. You won't be disappointed.

Papers for iPhone has a pretty short, gentle learning curve, but I still found the written documentation lacking. A video tour of the app comes preinstalled, and it showcases most of the app's features. On the plus side, Mekentosj has an active forum, and the developers are very responsive to feedback.

A full PDF viewer is included. It works in portrait or landscape mode, and supports zooming.

Features I'd love to see:

There's little about Papers for either Mac or iPhone that fails to live up to its promise. But as with all great tools, you're left wanting even more functionality. Here are the top items on my wishlist.

• Accept PDFs from e-mail. I don't know how feasible this is with the hyper-secure iPhone SDK, but it'd be magical to shoot PDFs from email attachments into Papers, and have Papers fetch the metadata from the cloud. (This is something Papers for Mac already does brilliantly.)
• More search resources. In particular, there are no facilities for searching books (Library of Congress), news (LexisNexis), or public reports (CQ Researcher, FedWorld). I'd love to use Papers for my journalistic research; this functionality would also make Papers an indispensable tool for anyone else whose research isn't restricted to peer-reviewed sources.
• PDF annotations. This is a feature I've seen many requesting on the desktop version. Circling and highlighting would be even more efficient and satisfying with Cocoa Touch.
• Citation alerts. I desperately want to throw the sites for Web of Science and PubMed over the bridge. The only reason I still have to go there is to maintain my citation alerts, so I know when my colleagues and competition release new articles, or when key papers are cited.

Papers makes it easy to send PDFs by email or -- if you bump into another Papers for iPhone user -- by Wi-Fi.

My Workflow

In case you're wondering how Papers fits into my larger workflow, here's my setup. I do all my searching and PDF management through Papers. Pages for Mac can export bibliographic information to .bib (for my own writing) and EndNote (for my adviser). My academic writing is all LaTex, for which I use TexShop. When it comes time to circulate paper drafts, I use PDFs, which my co-authors hate. On my next publication project I plan to try PDFtoWord.com, about which I've heard some good things.

For writing that doesn't require equations, I have always used text editors, but I'm looking into Scrivener. OmniFocus is my to-do list manager, and Keynote has been my trusted friend for countless presentations. iCal, Address Book, and Mail round out my productivity apps.

Most of our lab's data analysis is done in Matlab, with the occasional tromp through Excel. (I only use Office on Windows machines because it is interminably slow on the Mac.) I have used Google Sketchup for 3D cartoons and OmniGraffle for some 2D drawings, but haven't used either enough to bet the farm on them.

Bottom Line

Papers for iPhone is a perfect extension of Papers for Mac. If you work with journal articles, Papers for Mac is the best solution I know for managing literature. Once you're hooked, Papers for iPhone is a great way to take your literature on the go.