delicious.com

On delicious.com a tag is described as 'a word you can use to describe a bookmark' and that the result of  using tags 'is a better way to organize your bookmarks and a great way to discover interesting things on the Web'.  The larger the 'tag cloud', the more  popular the bookmark.
A site that I shall bookmark to further explore is https://cacoo.com/  this URL came up when I typed in the tag diagram.  The site allows a person to create a diagram, and more than one person can be on line manupulating the diagram at the same time.  The site is advertised as being free.  It appears that on delicious all the bookmark URLs have an RSS feed.
Interestingly, in May 2011 Delicious was acquired by the founders of Youtube.
I do not have a Delicious a/c as yet.  For some reason Yahoo will not accept my gmail address and password although I have veriffied this.  I need to sort this out firstly.