Nick Antonov sent this tip for working in a network environment with lots of projects. "Using Open, Save, Save As, Insert Browse, and similar dialog boxes is inconvenient and time consuming when browsing through long network paths and project directories. AutoCAD 2004 (and later) has the option to drag the folder from an open dialog window to the left side bar/banner that holds the standard shortcuts (such as Desktop, My Documents, Favorites, or AutoCAD's Place bar) and create a shortcut to this destination. It is very easy to switch between your most used folders no matter where you are. This method saves me the time and frustration of browsing through long project paths. Just drag the folder to the Places bar; then you can rename the shortcut if necessary. You also can remove shortcuts. Just remember that if the dialog window is open, drag folders to create the shortcut and then click Cancel to close the dialog window. A prompt will tell you that you made changes to the Places bar and will ask if you want to save the changes you made.

"Microsoft Office 2007 has similar option called My Places, but dragging does not work. Instead, right-click on the folder and select Add to My Places. Also in AutoCAD, you can go to the last visited directory when you select Open. In Windows Explorer, go to Tools / Folder Options / View / Files and Folders. The option Hide Extensions for known file types must be cleared. If it is checked, it will go always to My Documents when the Open command is selected."

NOTES FROM CADALYST TIP PATROL:
This is standard Windows behavior for any software that peruses a folder tree regularly. It's very simple to use and a real time saver. In AutoCAD, another option is to type in autocad (setvar "REMEMBERFOLDERS" 0), then create multiple desktop icons to initiate AutoCAD with the Start In option of the icon properties set to the various project folders. Then simply start AutoCAD from the relevant icon so that any accessing of the folder tree will go to the project folder by default.