I've always thought about what I would say or do to show someone a site like Twitter, Blogger, YouTube, etc. I think it's even more difficult to show a fellow teacher or colleague and try to "sell it" as an educational tool. Back in March of '07, I created my first Twitter post just because it was the next big thing. Since then, I've learned some great tips. Things I could easily suggest to an educator (or anyone skeptical of Web2.0).
1. Reel 'em in
This is the hard part for most of the services out there. Social-networking sites are only as useful as the network you're in. For Twitter, you sign up for free, but you have ZERO people in your network!
Try this: Send the message "track [keyword]" with [keyword] being something you'd like to receive Twitter posts on (teaching, for example). You'll receive IMs or SMS messages that include that keyword, which will instantly give you some people to start following.
I can count on one hand, the number of times I've needed to "nudge" someone. I've been "auto-nudged" (a Twitter feature available via settings) a few times though. So, you sign up your favorite team-teacher, and they fall off the wagon. Nudge 'em, especially if you know they're doing something spectacular (or even mildly interesting).
3. Share your Friends
If you're trying to recruit a friend of yours, there's a good chance you have similar interests. Maybe some of the people you're following would also be a good fit for your friend? You could showcase a few of your favorites in a blog post, by simply sharing the bookmarks to their Twitter feeds, or even sharing their screen-names over lunch.
There are my few tips to sharing the Kool-Aid that is Twitter. It's been almost a year for me, and now I look back (on page 49 of my archive and almost a 1000 updates), and realize how much I've learned from it. I also wonder where it'll take us, professionally and/or personally.
Please share in comments, any other tips you have for recruiting your friends/family/colleagues.