I was just recently tipped off about a pretty cool replacement for the Windows Quicklaunch bar called True Launch Bar v3.2. Overall, it seems to be a really good enhancement to Windows XP. The only thing I've found that I dislike is that I haven't found a good way to apply configuaration changes across different toolbars (you have the ability to customize each toolbar to behave differently--which is great, but often I want to make the same change across multiple toolbars.) I'm sure there's probably a way to do this and I just haven't figured it out.
I've always used multiple toolbars, I usually have the default "Quick Launch" toolbar and then a couple others for Remote Desktop Connections, VPNs Connections and Games. The nice thing about the True Launch Bar is you can configure a bunch of different virtual folders on a toolbar to really customize how Windows XP works. They even have "plug-ins" which are active items that run in a toolbar.
So, I've broken my taskbar into 3 different toolbars. The "Quick Launch" bar, a "Virtual Folders" bar and a "Plug-ins" bar. The Quick Launch bar shows the default items in the Quick Launch bar. I use these for the applications I use every single day that I want one-click access to. The "Virtual Folders" bar consist of icon shortcuts that pop-up a folder of shortcuts (which can contain subfolders.) Basically think of this as a bunch of specialized "All Program" folders. My "Plug-ins" bar currently has two plugins in it—the Battery Life and Wireless Signal plug-ins. These give me live feedback on my battery status and my WiFi connectivity.
Here's a cropped down version of my taskbar:
Clicking on any of the icons in the "Virtual Folders" toolbar gives me a pop-up window of shortcuts. Check out the screenshots on the True Launch Bar website for more examples of what you can do.