I'm a very keen user of Papers, the Mac software for collecting and organising a collection of journal articles and their associated PDF files. It never fails to impress colleagues when I pull it up and do a quick search to find some paper we've just been discussing. Now I won't even need to be in front of my computer to impress them, because Mekentosj have just released a version of Papers for the iPhone.
I've been playing with it for a few days now, and it's very well done. You can choose what you sync with your desktop version of Papers, so if you've got a huge collection, you don't have to fill your iPhone with it. I have a Smart Collection for my 'to be read' articles (which seems to grow by the day), so I've been syncing that. However, I might add a Smart Collection of my own papers too -- more about that later.
Most of the features available on the desktop version are available on the iPhone -- certainly all of those that make any sense on the platform are present. You can even use the search engines to find new articles and download the papers to read, which could be very handy. The PDF viewer works quite well, though there seems to be a little bug in the PDF viewer for third parties that means that some files are rendered with slightly blurry text, but I'm sure this will be fixed in time. I haven't found it a big problem with most files, and the convenience of being able to reduce my huge 'to be read' virtual pile in spare moments away from my computer overwhelms any minor issues with the display. You can also make notes on the paper, which are then synced back to the desktop.
I mentioned that I might keep a collection of my own papers on the iPhone. Why should I want to do that? Well, when you are viewing an article entry, you can choose to share the paper: either by email, or by sending it directly to nearby iPhone Papers users. I haven't had a chance to try out the latter, but I think that would be incredibly cool. Still, just being able to chat to someone at a conference or meeting about your work, then pull out your iPhone and send them a copy of the paper you're discussing, there and then, would be genuinely useful.