I finally joined Twitter - if you have one, you can follow me.
I discovered something interesting about trends by noticing something I did in the lead-up to my finally getting on Twitter. I had about fifteen conversations with people on Twitter explaining my reluctance to get one for all the normal reasons ("everyone just says what they're doing or what they just ate"/"it's just a popularity contest"/"it's just a fad"/"I don't want to be updating it constantly or having people constantly complain about how I haven't updated"/etc.) At the end of each conversation, I'd just say "yeah, I just really don't think I'm gonna get one." After a while, without really thinking about it, I suddenly just went online and got an account, telling myself "well, I just won't be one of those people who updates random crap constantly." At about the same time, a watched a couple other people go through the exact same process - we even had conversations together explaining how we weren't going to get on Twitter, and then we all did.
I think that when a new fad arrives, people need to have those conversations, where they make every excuse and explanation for not getting the new technology until they run out of enthusiasm for having this conversation over and over, and just go get the new whatever-it-is. You see this with people in my parents' generation all the time: they keep explaining how they don't want a cell phone, and won't use a cell phone, and are annoyed by cell phones, and then suddenly, without fanfare, they have a cell phone. You just reach a point where by constantly explaining to everyone else why you don't want something, you end up talking yourself into it.
Now I just need to find a way to exploit this.