There appears to be a lot of confusion and mixed information on the best way to do wallpapers for the HTC EVO mobile device. There are about four resolutions and a couple of techniques in various forums. I did some of my own research and this is what I found. I assume you are using a stock device and have not removed the base UI.
The EVO screen is 480 x 800 (pixels; all numbers are in pixels).
There are seven homes per scene; the middle and three to the left and to the right.
The best resolution for incoming images is 960 x 800.
When choosing wallpaper, expand the green boundary box to use the entire image. This results in the least amount of distortion of the final image displayed on the EVO homes.
The top 38 pixels will never be seen; they are covered by the status bar. If you have an embarrassing zit on your forehead or do not want to folks to know you are a NASCAR fan then make sure your acne and logos are in the top 38 pixels of the wallpaper.
The leftmost and rightmost 48 pixels will never be seen. On the left side, pixels 1-48 are hidden, 49-59 can be seen momentarily when swiping right when on the leftmost home, and pixel 60 bleeds onto the leftmost home. On the right side it is the same just in reverse; but the last pixel does not bleed into the rightmost home.
The bottom 56 to 70 pixels are usually hidden by the lock/menu bar except when you pinch and then select a home and when the device is locked. So food stains on your shirt, nipples and muffin tops would go in that area.
The extended homes do not have their own separate wallpaper. The center home is in the middle 480 x 800 pixels of your wallpaper. When you swipe in a direction to get to one of the extended homes the wallpaper is shifted 60 pixels in that direction (240 pixels on each extended side, 60 of those are not visible).
So start with a 840 x 762 image assuming that the bottom 60 or so pixels will be seen when the device is locked but usually will be hidden. Add borders (solid black is fine) to the top, left and right to make the image 960 x 800. Send it to your device using whatever method you choose and then enjoy.
Of course, someone from HTC will come along and probably debunk all of this but it works for me.