I like twitter better for updating my friends, and having on-going convos. Plurk is nice when I'm bored and want to talk to random people.

twitter for information gathering - news & plurk more personalized- talk to people

plurk better, like the conversations better.though it can more overwhelming than twitter.. twitter is easier if you don't have a lot of time

I like both of them...I have some of the same contacts but also different ones. I just like to meet new people and have interaction

plurk, don't know how to use twitter at all