In-house web monkey primarily working on the LAMP stack (Linux (Slackware), Apache, MySQL and PHP) and sometimes C#, Java and Perl on the side. I probably know more about Regular Expressions than is healthy and have a certain level of ninja skill with mod_rewrite.

(X)HTML, XML, JavaScript, JSON (AJAX) and CSS pretty much go without saying - and I think anyone who tries to sell you SEO as some kind of dark art is a snake oil salesman (make it work in Lynx, follow WAI guidelines and it'll pretty much BE search engine optimised by default).