Expert programming skills in PHP, Ruby or Python. (We are not particular about language as long as you are a quick learner).
Good understanding of web standards, CSS-based design, cross-browser compatibility.
Experienced at developing for the web (understand JSON / RESTful APIs). Extra points for Facebook app / mashup experience.
Familiarity with MVC frameworks such as Rails, Zend, Symfony, CakePHP.
Strong command of SQL.
Good understanding of web technologies (HTTP, Apache, MySQL) and familiarity with Unix/Linux. Extra points for experience with Lucene, Memcache.
You should have most of the skills and experience mentioned above and be enthusiastic about learning the rest.