I really hate when the Dock is too cluttered with large numbers of Icons. Lots of other people hate this too thus the popularity of many Dock extenders and alternatives to the Dock. I have found a way to quickly launch my favorite applications, files, and documents without having to add additional programs to my system.
If you open a finder window, you will see that there is a "Favorites" icon (heart icon) that you can drag things to, and a shortcut to that item will be automatically created by finder in ~/Library/Favorites. Simply drag the icon for ~/Library/Favorites to the Dock and it'll show up in the right half of the dock where your documents are parked.
To quickly launch a Favorite, just Control-click (or click and hold) on the Favorites icon in the dock and you'll be given a menu list of all your favourites. I even changed the ~/Library/Favorites icon to a ToolBox looking icon. You can change the Icon to taste. Now I can launch frequently used items quickly and easily without having any system bloat (ie better stability).
[Editor's note: Although this is a basic hint, and it's been mentioned here a couple of times in passing, many people may overlook it due to the Favorites folder being somewhat hidden inside the Library folder. If you like this, you may find that a customized shortcut folder works even better. The Apple Favorites folder, for example, won't let you create sub-folders or organize your favorites by type. I created a "QuickLaunch" folder (that's now bound to a custom MaxMenus keystroke as well as living in the dock) that contains folders for types of apps and documents. Within each folder is an alias to a favored application or document. Now I get a small pop-up and can more easily navigate to the favorite item I wanted. The only downside is that you can't just "Add to Favorites" through the menu; you'll need to hand-manage your customized favorites folder, but command-option-drag and spring loaded folders make it pretty easy.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20021218051831338