I'm answering my own question this time: How do you configure the Places Bar in Vista's standard file dialog boxes?
The Places Bar, on the left side of the File Open and Save dialog boxes, lists popular locations for saving files, such as Documents and Desktop. Unfortunately, Windows doesn't make it easy for you to change these locations, preferring a "Microsoft knows best" policy.
In past columns I've explained how to set customize the Places Bar in earlier versions of Windows, as well as in Microsoft Office versions 2002 through 2007 (Office has its own dialog boxes and Places bar, separate from Windows).
But what about Vista? It actually has two kinds of standard file dialogs, and they each work differently.
The first one looks like Windows Explorer:
No Places Bar here, but Windows Explorer's Favorites List does the same job. If you're not using that Favorites List in Explorer, you're missing one of Vista's best file-handling features. To add a folder to this list, simply drag it into the Favorites List pane in the upper-left corner. You can change the order by dragging folders up and down, and remove a folder from the list (don't worry, you won't delete the folder) by right-clicking it in Favorites and selecting Remove Link.
Things aren't so easy with the other Vista dialog box style, which looks like a pre-Vista dialog:
You can customize this kind in Vista Business and Ultimate, but not Home: Click Start, type gpedit.msc, and press ENTER. In the left pane, go to User Configuration/Administrative Templates/Windows Components/Windows Explorer/Common Open File Dialog. Double-click Items displayed in Places Bar. It's all pretty obvious from there, although you have to enter paths to your locations; you can't browse to them.
There's one other solution, and it works for any version of vista, older versions of Windows, and even for Office: A free, open source program called the Meloware PlacesBar Editor.