This Sublime Text 2 Package provides the ability to align all the equals(=) in the selected text. So it will change your code from this:
$a = 'some value';
$medium_var = 'some other value';
$very_long_variable = 'yet another value';
to
$a = 'some value';
$medium_var = 'some other value';
$very_long_variable = 'yet another value';
To install clone this repo into your Sublime Packages folder.
$ git clone https://github.com/trevormorse/AlignEquals AlignEquals
Select the text you would like to have the equals and then press alt+=
.