[EVO 4G Android Development] vinconti:
assuming that your phone is already rooted, and you have already flashed another recovery, then yes that file is the only one that you will NEED, although there might be some other files that you want. For instance, until the market/rom updates, the Google Voice app is not available on the market, so you will want to copy that manually. (i will tell you how to do that at the very bottom of this). you may also want your phone to look like a droid x, or save more battery, in which case you also flash those files.

You are undoubtedly coming off a stock, Sense rom. I would almost think about suggesting you hold off on this one, though, at least until you play with a purely AOSP rom so you can realize how freaking great this particular rom is.

if you don't know what recovery is read this paragraph. if not, skip it...there are basically a few ways to boot your phone. just like you could boot a Windows computer by either using the hard drive with a properly installed version of windows on it, or you could boot it by sticking a boot DVD in there, Android has something similar. The ROM you are installing will be your normal, properly installed OS, and the recovery partition is another section of your phone's internal memory, that you can use to boot the phone, just like the installer of a computer OS like windows. you can't do much in recovery except some basic things like flash a rom, or format partitions, and so on. the recovery that comes with the phone really sucks and basically won't work. if you haven't yet flashed another recovery, search for "rom manager" on the market. download it and click "flash clockworkmod recovery". then put this downloaded zip file into the root level of your SDCARD, back up all your data, and reboot into recovery (turn it off completely and then hold the down volume while turning on, or have the phone plugged in and type "adb reboot recovery" in a cmd prompt).

in recovery, choose the options that formats/factory resets your DATA partition, then the option that flashes a zip from the SDCARD. from there you should be set.

If you do want to try an AOSP rom (that means is very close to how Google originally intended it), you should try first flashing Cyanongen' http://mirror.teamdouche.net/get/supersonic/update-cm-6.1.0-RC2-Supersonic-signed.zip but you will also need google apps, which you flash the same way

http://forum.cyanogenmod.com/files/download/122-google-addon-hdpi-20101114/

finally, if you need to pull an app from your phone now so you can put it on the phone after you flash it, here is how. what you are going to do is download this latest version, then using a shell, navigate to it, figure out what it is called, and then use adb to put it on your computer. then format/erase/flash your phone, and after, there are a few ways of getting it back on your phone.

so download the latest version of google voice. go into the market, hit menu->downloads and make sure it is up to date. then plug you phone into the computer, and open a command window. type "adb shell" and hit return.

a # should pop up, maybe with some words or letters. type "cd /data/app" return, then "ls" return. it will list all your apps that have been installed or updated since you got the phone (but not before). Find the one you want (if it is google voice it will be called something like GoogleVoice.apk or com.google.voice-2.apk.

type "exit" return, make sure you are back at a normal command prompt, and type "adb pull /data/app/whatever_it_was_called.apk c:\user\your_user_name\desktop\whatever_it_was_called.apk" obviously, change the second path to where ever you want to put it.

then flash the phone. at this point, to reinstall it, either by typing in a cmd prompt "adb install c:\user\your_user_name\desktop\whatever_it_was_called.apk" to have adb install it, or you can manually stick it in the zip file before you flash it, in /system/app or /data/app depending on if you want to be able to UNinstall it later via the phone. adb install works more reliably because it also copies the libraries to where they have to go