The langpop link is interesting because it does an analysis by source. If you are familiar with Craigslist, you can see some of the problems with the methodologies. The SF Bay Area is heavily into web development, so PHP is no surprise. But C and C++ are second and third and essentiallt tied. That much C development going on? Not really. The majority of listing have C\C++ some where in the acronym stew, just to indicate that they want real programmers. So what were companies hiring a year ago, when last I looked? PHP, Java, C#, Ruby, and C++. All the rest was HR noise. But it's more interesting than nothing.