Google Play on Android 4.0 emulator

Download Google apps (GoogleLoginService.apk , GoogleServicesFramework.apk , Phonesky.apk)
from here.

Start your emulator:

emulator -avd VM_NAME_HERE -partition-size 500 -no-audio -no-boot-anim

Then use the following commands:

# Remount in rw mode.
# NOTE: more recent system.img files are ext4, not yaffs2
adb shell mount -o remount,rw -t yaffs2 /dev/block/mtdblock0 /system

# Allow writing to app directory on system partition
adb shell chmod 777 /system/app

# Install following apk
adb push GoogleLoginService.apk /system/app/.
adb push GoogleServicesFramework.apk /system/app/.
adb push Phonesky.apk /system/app/. # Vending.apk in older versions
adb shell rm /system/app/SdkSetup*

For future visitors.

As of now Android 4.2.2 platform includes Google Play services. Just use an emulator running Jelly Bean. Details can be found here:

Setup Google Play Services SDK

EDIT:

Another option is to use Genymotion (runs way faster)

EDIT 2:

As @gdw2 commented: "setting up the Google Play Services SDK does not install a working Google Play app -- it just enables certain services provided by the SDK"

After version 2.0 Genymotion does not come with Play Services by default, but it can be easily installed manually. Just download the right version from here and drag and drop into the virtual device (emulador).

I do this in a more permanent way - instead of installing the APKs each time with adb, permanently add them to the system image that the emulator uses. You will need Yaffey on Windows, or a similar utility on other systems, to modify YAFFS2 images. Copy GoogleLoginService.apk, GoogleServicesFramework.apk, and Phonesky.apk (or Vending.apk in older versions of Android) to the /system/app folder of the system.img file of the emulator. Afterwards I can start the emulator normally, without messing with adb, and Play Store is always there.

Obtaining the Google Play app from your device

Downloading Google Apps from some Internet site may not be quite legal, but if you have a phone or tablet with a corresponding Android version, just pull them out of your device:

adb -d root
adb -d pull /system/app/GoogleLoginService.apk
adb -d pull /system/app/GoogleServicesFramework.apk
adb -d pull /system/app/Phonesky.apk

You must have root-level access (run adb root) to the device in order to pull these files from it.

Adding it to the image

Now start yaffey on Windows or a similar utility on Linux or Mac, and open system.img for the emulator image you want to modify. I modify most often the one in [...]\android-sdk\system-images\android-17\x86.

Rename the original system.img to system-original.img. Under yaffey, copy the APK files you pulled from your device to /app folder. Save your modified image as system.img in the original folder. Then start your emulator (in my case it would be Android 4.2 emulator with Intel Atom processor running under Intel HAX, super-fast on Windows machines) and you'll have Play Store there. I did not find it necessary to delete SdkSetup.apk and SdkSetup.odex - the Play Store and other services still work fine for me with these files present.

When finished with your testing, to alleviate your conscience guilty of temporarily pirating the Google Apps from your device, you may delete the modified system.img and restore the original from system-original.img.

1. Download the gapps package from http://goo.im/gapps
2. extract GoogleLoginService.apk,GoogleServicesFramework.apk and Vending.apk Go to cmd window type adb shell
   3. on the shell type mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
   4. then press Ctrl+c to exit. cd to the directory where apks has been extracted,
   5. type adb push <appname>.apk /system/app
   6. then type adb reboot

You could download it from a Android 4.0 phone and then mount the system image rw and copy it over.

Didnt tried it before but it should work.