I'm breaking my silence briefly to respond to an interesting question from Amy Gahran, who asks 'Starting conversations online, what's different?'
For me, as with Amy, it's the element of control you have. You decide when, where and how to start a conversation, you hold the cards. You might take part in a conversation you wouldn't normally go for in a face-to-face situation. You might not cover a wide range of topics, as you might in person - rapidly moving from one topic to another.
You can also choose when to stop, when things are going beyond your level of knowledge or when you think an argument might be just round the corner! However, of course, if you're discussing something and need evidence to back your argument up, its all there at your fingertips. I've had chats with people on line a few times and admit to having felt slightly smug at being able to whip a set of statistics or an article up straight away to back up my line of attack!