Social bookmarking

"kuk mal hier" or "po smatrit": Social bookmarking for scientists using Connotea, and "Ontology is Overrated" This is an entry from Connotea, pointing to someone's blog. I'll read it when I get a chance. There are too many places to save links to! Either this blog, my library on Connotea or Delicious, or as a conventional bookmark. How do people decide which to use?