Endnote is, according to their makers, the bestest citation software ever. As is Zotero (according to their makers). And probably a bunch of others as well.
Back when I was still trying out stuff and relatively new to the world of people working in physics (who have an affinity to
LaTeX-the-programme), I wrote one article in TeX. I had to re-do it in MS Word to get it published, but this little stint meant that I got to know the powers of BibTeX, which is the citation system thingie that comes with TeX. It is, more or less, a reference database that you cite from, and the programme does the formatting.
Sound familiar? That's just what EndNote does with Word. Back when I then found out that there was, indeed, such a programme, I bought it for the hefty sum they asked for the student edition back then and have been using it ever since. There's connection files to get data from online library catalogues (something I should have used more, I now think, it might have saved me lots of work), style files that can be altered to suit individual needs, and both a field for "notes" (which I use for making general, personal notes about a reference) and "research notes" (which I use for typing excerpts or snippets including the page number so they can actually be used for working without the physical copy of the book). Plus there are custom fields - those I have used to mark whether I own a book (physical or digital copy), where it stands in my library (well, that's a work in progress to be honest), if I have pictures in my picture database (by noting down the prefix of the image files, such as schweppe_ which is, in the actual files, followed by a page number so I have files like schweppe_10.png) and if I have already read it or just jotted it down for future reading.
According to the version history, my purchase of the programme must have been in 2004. Which means that my version is a little... older. Now, I have no problem with older software (I'm happily using Word2000, and not planning to change from that), but sometimes, it pays to look for alternatives. Especially since my EndNote is sort of iffy on the connection files, with quite a few of them not working (or not working anymore), and I cannot download the whole set of new ones from the site (there is no such button in my installation menu).
Due to the recent mention of Mendeley by Phiala in the comments of some other post, I did a little looking and found
Qiqqa - a .pdf organising software with built-in OCR, a wizard to help with filling out the reference data for each imported .pdf, and the possibility to cite to Word. I quite like it on the first try and am currently using it to get some order into my .pdfs. I have even considered changing to this programme from EndNote for all my referencing, but it does not do a few things that I have grown accustomed to, and I have also read that it's not too easy to modify citation styles (something I regularly need to do).
Qiqqa is intended for use over the web, with web storage of .pdfs, something which I don't need (and don't want). It allows "vanilla references", that is those without a .pdf attached, but then I get a nasty popup if I want to associate a file with it now. It also does import from EndNote - but not the "Research Notes". There is the possibility to search for duplicates, but I found it rather hard to compare the actual duplicates with each other and decide which one should stay and which one should go. I have not tried the citation thingie yet, but from the overall feel, it's very much geared towards .pdf files only, and I don't want to use two programmes. So at the moment, my plan is to use Qiqqa to get some order into my .pdf files, then export the data via BibTeX and a converter to EndNote, and merge the two databases. (That's the plan only, though - and it might change if problems with the import should arise. Or if Qiqqa should evolve some more, and then I might reconsider using it as my new reference database thingie.)
I'd be happy to hear about your experiences with Qiqqa, EndNote, Zotero or whatever you use!