Cal Henderson has been a web applications developer for far too long and should really start looking for a serious job. Originally from England, he currently works at Yahoo! Inc in San Francisco, California as the Director of Engineering for the photo-sharing service Flickr. Before Flickr, he was the technical director of Special Web Projects at emap, a UK media company. By night he works for a whole slew of web sites and communities, including the creative community B3TA and his personal site, iamcal. In his spare time, he writes windows software, develops web publishing tools, and writes occasional articles about web application development and security.