Well, it all depends on what you want them to use it for.
I have zero interest in knowing when my friends are eating a sandwich, and sadly, that's the only types of updates 90% of them make. I wish I could convince them to get off Twitter.
Other than that, the best way to show them the utility of Twitter, I would think, would be to show them people who use it well. Don't show them a stream of "eating sandwich", "that was a good sandwich", "going to the bathroom brb", "okay poop is coming out now" updates.
Then when I was at PyCon last month, they put twitterfall with the #pycon keyword up on the projector before the morning sessions started and during lunch and I saw that it could be a lot more than 'eating a burrito' updates.
As far as your friends go, I say tough love. Just drop them and when questioned explain why. Either that or write a Greasemonkey script to drop them from your main stream.
I have zero interest in knowing when my friends are eating a sandwich, and sadly, that's the only types of updates 90% of them make. I wish I could convince them to get off Twitter.
Other than that, the best way to show them the utility of Twitter, I would think, would be to show them people who use it well. Don't show them a stream of "eating sandwich", "that was a good sandwich", "going to the bathroom brb", "okay poop is coming out now" updates.