What the hell are Digg, Del.icio.us and StumbleUpon?

BigBouncyBall

following on from my twitter thread, i thought i continue my education about the 21st century and ask about these services:

Digg

Del.icio.us

Stumble Upon

What are they, are the worth using, do you use them regularly? I suspect they're more useful than twitter after a quick look at them.

answers on a postcard please.

hotkee

They monitor blogs and other types of sites so you can track when blogs get updated, tell others of interesting sites etc.
Sort of twitterish without being becoming a follower - tried twitter myself for less than a day, closed account - kind of sad I thought.

kwikbreaks

I use StumbleUpon.

On FireFox there is a toolbar which goes with it. You select categories which interest you then hit the Stumble button and it throws up a random site for one or other of your categories which other users have recommended. It's a good way to find interesting pages and sites. You can vote on and recommend sites you come across.

Digg and Delicious are similar (I think - I haven't checked them out).

devizes18193

Delicious store your bookmarks online you can chose to share them or not and are searchable , there is a random button which will take you to a random bookmark but its not definable by topic like stumble is

Millionaire

You know, Google is your friend. It will introduce you to Wikipedia and you can have a 21st century orgy.

http://en.wikipedia.org/wiki/Digg

http://en.wikipedia.org/wiki/Del.icio.us

http://en.wikipedia.org/wiki/StumbleUpon