The scientific service of the German Federal Parliament has published a small whitepaper (just two pages) about what Second Life is in a nutsthell. The PDF is in German only, of course, but if you're interested, you might want to give it a read.
There's a new hype in the town called "Web 2.0" hype - it's being called Twitter. What it is about?
To cite themself:
A global community of friends and strangers answering one simple question: What are you doing? Answer on your phone, IM, or right here on the web!
So it's basically about you telling the rest of the world what you're doing right now in your pitiful life. Not more or less, period.
Frankly said: why should I care about that rubbish at all? I value my privacy and for sure I am not going to tell the whole Internet what I am doing right now, where it still can be found after years and forever!
For an example, how this might look like, just follow this link. So it's basically a very stripped down form of a diary with some community features around it. Period. Boooring...