This little plugin I created allows you to open the api site at the Drupal 7 documentation for the currently selected function.
Installation
This plugin has been submitted to ST2’s excellent package control repository which make it super simple to add.
Open the command palette (cmd-shift-p) and choose "Package Control: Install Package" then "Goto Drupal API"
You can also manually install it from github:
https://github.com/BrianGilbert/Sublime-Text-2-Goto-Drupal-API