Thanks for your comment Gary. CiteULike is great too, and researchers should use whichever one works best for them. We haven't built any custom code that would favor (or disfavor) any of the social bookmarking/social citation tools, and for now are mostly trying to expose folks at Duke who might not already have encountered them to the possibilities these types of tools provide. We should post a LibraryHacks item on CiteULike soon, or maybe just link to the ones you've already written. :-)

When we first started exploring social citation tools as the potential base for new library services, we looked at a bunch of them, including Connotea and CiteULike, as well as PennTags, H20Playlist, Scuttle, and Unalog. There were things we really liked and things we wished were different in all of them, but we decided to start with Connotea as one we would do most of our initial experimenting with for a couple of reasons: it is GPL licensed, and we thought we might want to install a local instance at some point and possibly do some customization for Duke users (like Duke NetID authentication); it seemed to have a fairly large user base already, or at least critical mass to demonstrate the social benefits of using it; it had good documentation for beginners; it is supported by the Nature Publishing Group, which we thought made it less likely to disappear soon (if the individual developers of some of the other systems decided to stop supporting their tools for whatever reason).

Still, we recognize that each of these different systems has strengths in different areas, so ideally we'd help Duke researchers find and use whichever one is best for their particular situation. Advice from folks like you who are expert users of several of them is most welcome!

What I'd like to see is something that combines the best of each of these with Duke's catalog, WorldCat, LibraryThing, Netflix, and a few others. Maybe we're headed in that direction with Zotero or the TagCommons initiative...