Programming languages and technologies:
OOP, MVC, Facade, Bridge, Abstract Factory, Strategy, Adapter, Observer, Singleton, Decorator, Factory Method, Template Method
Flex / Flash (custom UI components, states, effects, styling, AMF, ExternalInterface)
PHP (smarty, curl, soap, sockets, memcache, json etc)
JavaScript, AJAX
SQL: MySql, Mysqli, ADOdb (joins, explain, indexing...)
XML (XHTML, XPath, DOM)
Flex frameworks
Cairngorm
PureMVC
PHP frameworks:
Drupal: theming, phptemplate, creating own modules, customizing existing modules, hooks, forms API
Zend framework
PureMVC
JS frameworks:
EXTjs, JQuery
CMS:
XT:Commerce (and clones: ZenCart, VamShop, OsC) theming, customizing and creating modules, intergate with other CMS
Wordpress: theming, using existing modules
ModX: theming, using snippets from community
Joomla: theming, using existing modules, customizing & tuning
Wiki: theming, customizing & tuning, intergate with other CMS
PhpBB: theming, customizing & tuning, intergate with other CdMS
OS:
Linux (bash, coreutils, LAMP administration, rpm/apt, ifconfig, iptables, route,service, cron, rsync)
windows (advanced level)
Mac
Development tools:
Adobe Flex Builder
FlashDevelop
Codelobster (for Drupal)
Eclipse (PDT, SVN, FTP)
FireBug
Zend IDE
Gedit + plugins