AppWall puts all your HTC EVO apps on one screen
There are several ways to fit more app shortcuts on your HTC EVO home screens.
Some of them include widgets like Multicon or Launch-X Pro and various third-party launchers that let you increase the number of columns and rows. Another option is to use AppWall, a full-screen widget that displays all the apps installled on your EVO on a single screen.
Tapping the widget, which actually seems to stretch the icons a bit and make them a little fuzzy, "wakes up" AppWall so that you can launch apps from the active overlay (which contains clearly rendered, non-stretched icons) that appears in the foreground. When you drag your finger across the icons, a small window is displayed that shows you which app you're touching; lifting up your finger will open the app.
If you don't want to use the widget, you can also just launch AppWall like a regular app. Doing so will bring up the active overlay mentioned earlier, which is better in some ways since it saves home screen space since you're not using the widget. You also never have to see the mildly distorted icons.
I just flashed a new ROM and am still in the process of restoring my apps (I don't do batch restores) so I don't have enough installed right now to find out what AppWall does if it can't fit everything into a single screen.
If you have a lot of apps on your EVO, you can find out by checking out AppWall for yourself.