TOOLS FOR FORMATTING & MANAGING CITATIONS
Zotero http://www.zotero.com/ This is a Firefox browser-based system for bibilographic management; however, there are now Chrome and Safari extensions that expand Zotero's usability. Also, Zotero is now cloud-based, enabling you to access your Zotero account from multiple devices. Zotero allows you to drag and drop documents right into your Zotero library.
Mendeley is a very user friendly, non-browser dependent, citation management tool, compatible on both Macs and PCs. Mendeley is a desktop based program but data can be backed up to the cloud; Mendeley can also be downloaded to multiple devices and data can be synced.
Free to anyone. It can be used with any web browser. It allows you to store and share citations via the internet. It also allows you to save .PDFs along with your citations and save then to your CiteuLike account.