Due to my study I have to read a lot of papers and, therefore, organize the bibliography in some way. The first software that I found for this purpose was EndNote. However, I don't like the idea of storing all data on a local drive, especially when you need to access the information for several computers. I started to look for something else and found a very nice and convenient tool called Zotero (http://www.zotero.org/). All data are stored on their server and you only need to install Zotero's extension for Firefox that will automatically synchronize with the server.
Everything is fine except absence of data about number of citations. Usually, you need to choose the most recent or the most cited papers. The first solution was just to find the number of citations in Google Scholar and enter it manually for each paper. Unsurprisingly, after a hundred of papers I found this solution inefficient. So I decided to develop a simple plugin for Zotero that will do all work for me :)
All you need is to install the plugin and add the field Call Number to the papers listing table. I chose this field because I don't use it and Zotero doesn't have any special field for the number of citations. Citations will be automatically fetched from Google Scholar for each new paper. For old papers it is possible to update this number, which is useful because it may change over time. You can update it for a particular paper, a collection or all papers at once.
Finally, here is the most important thing — the download link :)