Drilling through a succession of nested folders and subfolders in the Finder to find the one file or folder you want can be slow and inefficient. If you know the exact folder you want, you can use Finder's Go -> Go To Folder (Shift-Command-G) to streamline that process. One anonymous MacOSXHints reader found a way to make that menu item even more useful:
If you're manually entering a path in Finder's Go to Folder dialog (Go -> Go To Folder), pressing Tab will auto-complete the folder name--assuming you have entered enough information to make the choice unambiguous. For instance, entering /e and pressing Tab will auto-complete to /etc/ (assuming you have no other folders beginning with e in the root folder).
Not only will this save you time clicking through folder trees, it's especially useful for accessing hidden folders; even if the folder is hidden, it will show up in the Finder if you enter its name in the Go To Folder dialog. While there are many ways to toggle hidden files on and off, if you just need to briefly access one hidden folder, this trick works great.
This story, "Autocomplete Folder Names in the Finder" was originally published by Macworld.