http://ifttt.com/ via Viktor Benei's subjotThe service itself is very hard to explain. It's up there with Syphir's old interface though in terms of being user friendly.
Basically if you post something in a website, you can auto-post elsewhere.
The great part about it is that newbies don't have to create a task at all as it's possible to pre-share tasks.
I currently have the service update me on now shared tasks via Google Talk: See here:
http://ifttt.com/recipes/1673and
E-mail me when someone mentions (not dm) me on Twitter:
http://ifttt.com/recipes/2668Edit:This looks kind of cool too. Favorite tweets instantly go to Evernote:
http://ifttt.com/recipes/2382Edit #2:Oops. Sorry, just saw this iftt and realized this may have been posted elsewhere here already. Nevermind this topic then:
http://ifttt.com/recipes/2470