Once upon a time, if you had a problem with, say, Perl, you went to a forum, checked the forum rules, signed up, and asked a question, which eventually would get you an answer. Then you had a problem with MySQl, and you went to another forum, and asked a different question.
A forum for each topic is tiresome. Someone made an improvement, and then you have forums where you can ask pretty much anything.
But also that is not as general purpose as the concept of LazyWeb. When you need help, you just want to stand up and ask.
Here comes Twitter.
No additional subscriptions needed. Just the Swiss Army knife of the web questions. And you are not limited to geeky questions, you can ask anything.
Naive Twitter users may think that when you ask a question, only your followers can hear you. So if you have 50 followers, you don't stand a chance of getting an answer. Not so. Try this. Using Twirl (but also the simple twitter search would do), you create a new search, "activate it", and add it to your "home". Presto! you will be now receiving twitters that match your search, no matter if they are followers or not. The whole world is at your disposal.
You may be the one asking, and be surprised when you get back an answer in minutes from a complete stranger, or you may know the answer for one of the "lazyweb" questions, and feel compelled to respond.
Well, maybe the forums aren't dead yet, but surely they have a fierce rival.