Ctrl+D performs the find_under_expand
command in sublime. This basically searched for the next occurrence of the already selected text and selected it, so when I edit, it's edited on both places at the same time. I'm currently trying to move to IDEA editors (such as WebStorm, PHPStorm, PyCharm, etc) but didn't find something like this command in this IDE yet.
I believe they recently added this to the latest IntelliJ release, and I would assume PhpStorm as well. As the bindings are system specific, take a look at http://blog.jetbrains.com/phpstorm/2014/03/working-with-multiple-selection-in-phpstorm-8-eap/. Looks like that version is available through EAP, so don't know when they will release it for general consumption (or if they have already).
Alt+J on Windows and Linux, Ctrl+G on Mac OS X