LauncherPro is a free Android app that lets you strip down and customize your Android interface without any rooting, hacking, or coding. Set the number of home screens, customize your dock, or modify the appearance of your Android OS by way of an exhaustive menu of Preferences.
After installing, press Home, and choose to "Complete action using" LauncherPro instead of your device's stock interface (e.g. HTC Sense for HTC EVO owners). Then, press Menu, and go to Preferences (not Settings) to start exploring the world of customization possibilities. You can set your number of home screens and choose from different transition effects when shuttling between them. You can also tinker with your icons, Dock, layout, and countless other cosmetic elements. Some of our favorite features include a sweet 3D App Drawer effect and Hidden Apps, which can put away some of that stuff that came preinstalled by your carrier.
Overall, LauncherPro is a highly recommended download because it effortlessly opens up a world of customization options for your Android interface. However, we did find ourselves wishing it came prepacked with some widgets to boot. If you're wishing for the same, you'll have to pay $3.49 for the premium version.