Thing 14 includes not only Delicious but also Mendeley.
Mendeley is a free online reference manager software and on first impressions it gets a thumbs up. I will say at this point that I haven't actually tried using it but I watched the series of 'Mendeley Minute' help guides and I was very impressed. I didn't create an account partly because I don't actually need to manage any references, and partly because I read the warning that installing the add-on might interfere with Endnote, which I do have to use for work.
The reason I use Endnote is to import references from reading lists but that is all I do; I'm not the one who uses the data once it's in there and my feelings based on my very limited experience are that I don't like it. It doesn't feel user friendly, the interface does not appeal to me, and the methods of import seem clunky compared to other systems I have used, such as ePrints.
However, I see the value in reference manager software and if I was to set out on a research path I would try Mendeley. From watching the help videos it looks straightforward and logical; easy to import and sort references, easy to insert the references into your work, and easy to arrange the bibiography in the style that you need. I did a quick Google search on Endnote v Mendeley (that was not my actual search query!) and the only downside to Mendeley that I came across was the inability to use a modified referencing style, for example those used by several University of Southampton departments.
I came across this blog post on the University of Warwick PhD Life Blog which gives a nice summary of the positives of Mendeley.
So although I am not planning to use Mendeley it looks like a useful and user friendly free tool that I would definitely choose over Endnote.
I did read through the optional extra task of looking at Endnote Web and although I would like to do it so I can more fairly compare Endnote with Mendeley I don't have time this week.