''For your career, a blog is essential." So asserts Phil van Allen, a faculty member at the Art Center College of Design in Pasadena, as quoted by columnist Penelope Trunk in The Boston Sunday Globe.Oh, yes, a blog is essential for your career \u2013 much like tuba lessons, having the right vowel for a middle initial, and just a hint of cumin.There must be a limit to the delusions of grandeur that blind blogging enthusiasts -- but to date all I see are fellows such as van Allen who continue to raise the bar. Sure, blogging might be good for your career -- if you're good at blogging and your chosen profession \u2026 and you manage to avoid self-inflicted wounds.On the other hand, a blog might actually limit your future employment options. For example, I\u2019ve just shot all to hell my chances of being hired at the Art Center College of Design in Pasadena. \u2026 Pity.