Papers vs Mendeley
From enfascination
Papers and Mendeley are two PDF viewer/organizers crafted for scientific publication. I've never really bought much software, but if you are on a Mac, I recommend that you give Papers a try over Mendeley. It must be purchased after 30 days, but is totally worth it. I use it to take all of my notes, build all of my reference lists, and of course keep all of my papers.
When I want ideas for a paper I'm writing, I look at what I've already
written on the article. When I want to know what journals to submit to, I sort my paper collection by journal to see what I read the most in what category. When I want to know what Japanese researcher to work with this summer, I type in the word Japan to search PDFs, notes, journal titles, and whatever else to see what institutions I am reading work from. When I am writing a paper, I collect everything relevant to it in a folder. When I want the bibtex for that library of papers, I export it (though I've had to use Bibdesk as an intermediary to clean the .tex). When I want to share a paper, I drag it into Gmail.
At this point Mendeley does some things better (it is currently better with bibtex, it stores non-PDFs, it is cross platform) and some things worse (search is + better in Papers, note taking is ++ better, reading is ++, interface is +++, speed is ++ or +++) and some things just different (the way the two handle auto filling of metadata, Mendeley's social network thing).
Until a week or so ago I was a little concerned that my preference for Papers over Mendeley was just the sunk costs speaking. It would be really hard to switch at this point. But I tried anyway and moved my entire paper collection over. I gave Mendeley a really fair try, and came out decisively in favor of Papers. No more regret. Plus the developers are very transparent about their future plans and it looks like my biggest qualms with the software are on their short list. I know it costs money ($40 after 30 days), and Mendeley doesn't, but I also know that the Mendeley folks are crippling certain features so that they can start charging soo as well.
So yeah, Papers by mekentosj is worth a try.