I use all the time, love it. I’m definitely loinokg forward to more screen scraping though, and more export options. One thing that might make bibsonomy attract more users fast is if they added something like the export options; if you can convince a first-year student that this site will give you a quick and simple reference list for pasting into your Word document, in APA style and everything, then you’ve got it sold. Right now, bibsonomy is great for geeks, but not so much for everyone else.I tried Zotero, but since I use Opera and not Firefox it seemed rather pointless (also, I hate having slow extensions running constantly, when I only use them for five minutes at a time maybe Zotero’s better suited for site-specific browsers). Regarding copyright; I’m pretty sure that the pdf’s you upload can only be read by you, so it’s basically like having it on your private email account / drive.