Tagging, folksonomies & social bookmarking in Del.icio.us

Site options: Many very useful sites- I clicked on "Yarra Plenty Online Learning" which was bookmarked by 59 others & 13 people wrote notes. Related tags seem to cover it all.
"Mappr! Where It's At" was saved 1038 times & 265 wrote notes.
The Commoncraft Youtube video really does explain Del.icio.us in user friendly terms. I love these little videos.
I can see the potential of this tool for research assistance, as well as for information sharing for example, a group of teachers, as in the demo video. Yes it is an easy way to create bookmarks that can be accessed from anywhere, a great way to bring all related sites together on one site, & other people have done all the web searching!!