Q:

How can I use the Mac file selection menu in my own program?

In almost any desktop application that I've used, it's possible to select a path to open or save files using what appears to be a standard file navigator that looks just like Finder. For example, if I go to save this webpage, 
this menu comes up, and I can select where to save it, create a new folder, etc. Is there a system call to start this menu from my own program, and presumably return a path to the selected file or folder?

A:

Have a look at NSOpenPanel.
It does exactly what you seem to be looking for:

The NSOpenPanel class provides the Open panel for the Cocoa user interface. Applications use the Open panel as a convenient way to query the user for the name of a file to open.

