I sure did. Not having a Mac, I really missed the Papers app. I recall doing a search in late 2009 or early 2010 for a Linux friendly equivalent, but not turning up anything. Well, I wish I had kept at it, because it seems like Mendeley launched in March / April 2010. Seems to have everything that Papers offers, plus a web presence so you can sync your library across your workstation / laptop, plus maintain a web interface. It does a better job than Zotero / CiteULike at populating the all important meta-data of the papers I’ve tested, and more importantly, has highlighting & markup capabilities built in. This last feature was desperately missed in Linux, and now effectively means I don’t have to print out papers to annotate them, thank goodness. Seems to be available for all major OSs, including iOS for your iPad / iPhone. Not sure if other tablet OSs are supported, but it’s definitely worth checking out.
Looking back at the last two years, I’m sure I can attribute some of my lack of productivity in terms of papers not published to a lack of a serious knowledge management system such as this.