In a new article from PHP-Coding-Practices.com today, Tim Koschuetzki offers a different sort of solution for working with those little temporary variables scattered throughout your code - replacing a temporary variable with a queryable structure.
When you are using a temporary variable to hold the result of an expression, extract the expression into a method. Then replace all references to the temp with the new method. The new method can then be used in other methods.
His suggestion basically replaces the quick temp variable with something slightly more complex but something that can be used anywhere in the class. He uses the example of multiplying an amount times the quantity - first just assigned to a temporary variable inside a method then refactored as the result of another method returning the same thing (but accessible from anywhere).