Personally, I prefer to give new technology some time to mature before using it on anything important (and, as result, becoming competent with it), but I do try

Personally, I prefer to give new technology some time to mature before using it on anything important (and, as result, becoming competent with it), but I do try to look into new stuff just to see the ideas and approaches behind it. For example, when Rails was new, I built a small personal project with it (http://notifyr.com/ http://notifyr.com/). It was a pain to deploy and I wouldn't use it on a production site (not that it couldn't be done, I just didn't want to deal with it. We're talking pre-Mongrel), but understanding concepts like MVC or CoC changed the way I was coding PHP profoundly, and made it easier to get competent with Rails once it was more mature. (There is an exception, though: Some people make a living following tech hype. When a new technology starts getting mentioned in places like Wired or the NY Times, there's bound to be an unmet demand for coders who can use it. This can be pretty lucrative, but OTOH working with people who get their tech perception from these sources can be, er, interesting) As for knowing stuff like CSS, JQuery, Prototype etc, I treat it like foreign language - you need to know enough to get around, perhaps express simple ideas or read the newspaper if you stay for a while. But you rarely need to know it at a Shakespeare level.