I've just started wrking on a new codebase where each class contains a shared_ptr typedef (similar to this) like:

typedef boost::shared_ptr<MyClass> Ptr;

Is the only purpose to save typing boost::shared_ptr?

If that is the case why not do

#define Ptr boost::shared_ptr 

in one common header? Then you can do:

Ptr<MyClass> myClass(new MyClass);

which is no more typing than

MyClass::Ptr myClass(new MyClass);

and saves the Ptr definition in each class.