I would argue that San Francisco would be at the top of the list. I live in Los Angeles and often when I've asked successful tech businessmen why they live here rather than in San Francisco, it has to do with lifestyle and glamour and not so much the business itself.
We open-sourced a javascript port of Excel's numerical formatting, providing versatile text representation for numbers, dates and times. We use PEG parsing to generate the format and wrote a blog post about some of the interesting technical challenges. Would be great to get some feedback on the library (and blog post) for anyone who might be interested.