Add your folders to the Open / Save dialogbox

This is the Windows XP Pro way to customize the Places Bar (folders listed on the left of the dialogbox) in the standard Open / Save dialogbox.

1. Open the Group Policy Editor by opening the start menu -> run -> gpedit.msc
2. Drill down to Windows Explorer User Configuration -> Administrative Templates -> Windows Components -> Common Open File Dialog
3. Double-click the Items displayed in Places Bar setting
4. Make sure the setting is Enabled
5. Customize the Place to display with your folders*.

* - You can use Common Shell Folders by using any of the following folders: CommonDocuments, CommonMusic, CommonPictures, Desktop, MyComputer, MyDocuments, MyFavorites, MyMusic, MyNetworkPlaces, MyPictures, Printers, ProgramFiles, Recent

Now you're saying what if I don't run WinXP Pro? Well you need to either use TweakUI or edit the registry directly.

Registry location:
HKEY_CURRENT_USER -Software\Microsoft\Windows\CurrentVersion\Policies\comdlg32\PlacesBar

String value (name will be Place0 to Place4):
"Place0"="c:\\temp"

The above will only work for the Windows dialogbox and not the Microsoft Dialogbox. The following can be followed to modify these dialogboxes too: Office 2000 | Office XP | Office 2003

...some additional hacks can be found in Veign's Registry Hacks...