This site compares two popular social media sites, del.icio.us and StumbleUpon and tells you the advantages of both sites. From personal experience, StumbleUpon is very addicting and can be detrimental to your life... but totally awesome! As for del.icio.us, I had never heard of it so I found it very interesting.
With the use of stumbleupon, you can come across any website that has ever been created on the public internet. You can choose specific topics to look at or you can just stumble across the entire web.