Although Windows 7 (and Vista) make it easier to find folders, thanks to the Favorites and Libraries, some applications use the older Open/Save common dialog. And yes, it still supports Places Bar. You can add up to 5 places to it, replacing the five that are on it by default.
You can add your own places one of two ways: using the Group Policy Editor or by editing the registry directly.
Group Policy Editor
To use the Group Policy Editor, type group policy in the Start menu's search field and open the group policy editor ("Edit Group Policy") when it's found.
Browse to User Configuration > Administrator Templates > Windows Components > Windows Explorer, Common Open File Dialog. Note: in Windows 8, it's File Explorer, not Windows Explorer.
Edit the Registry
Open the registry editor by typing regedit in the Start search field and open it when found.
Browse to this path:
Create the following keys if they do not exist:
When finished, the path will be:
Under Placebar, create the String Values for Place0, Place1, Place2, Place3, Place4.
Double click on the String names and enter the paths you want on the places bar.
Close the registry editor and enjoy.