If you're not satisfied with the application switching possibilities that the Dock offers, then you'll probably enjoy what Paradocks has in store.
Paradocks is a clone of the classic application launcher that was used in OS 9. It works by creating a floating window in the menu bar containing the icons of all applications you're currently using and allows you to switch between them instantly. Although I never used OS 9, Paradocks reminds me a bit of the way you can switch between applications in Windows along the bottom tool bar.
You can customize Paradocks to a certain extent, and it allows you to change its size, location on the desktop, transparency level, icon appearance, switch between a vertical or horizontal menu bar, and configure hotkeys to access it. It is definitely easier than scouring through your Dock to see which applications you have got open.
Although Paradocks is a nice idea, it doesn't really offer anything that Dock switching doesn't. However, I can definitely see how Windows users that have just switched to Mac might find it helpful.
If you're nostalgic for OS 9 or are have just switched to Mac from Windows, you may find Paradocks a handy utility.