How To Install Android On iPhone 2G/3G Using iPhoDroid
Manually installing Android on iPhone is a painful process. For those who prefer to have it done in easy steps, here is a free tool called iPhoDroid which lets you install Android on iPhone 2G and iPhone 3G. Here are the steps to install Android on your iPhone along with iBoot in a dual boot mode, using iPhoDroid.
Prerequisites
1. iPhoDroid works with jailbroken iPhones on firmware 3.1.2. So downgrade iPhone 3.1.3 to 3.1.2, if required.
2. iPhoDroid currently works only with Mac OSX.
3. Install OpenSSH on your iPhone and connect to a Wi-Fi network.
4. Install MacFuse on your iPhone.
1. Follow the steps to Jailbreak iPhone 2G 3.1.2, or jailbreak iPhone 3G 3.1.2 if your iPhone is not yet jailbroken. Use only redsn0w, Blackra1n, or Sn0wbreeze to jailbreak your iPhone 3.1.2, not Spirit.
2. Download iPhoDroid for your Mac OSX and extract the zip file. (download link at end of post).
3. Double click the application to start the installation process. Select your iPhone model (iPhone 2g/iPhone 3G) and click ‘Next’.

4. Then choose ‘Install’ and click ‘Next’. If required enter your admin password.
5. In the next step, you will be asked to enter your iPhone IP address. The steps to find this are given here.
6. Enter your iPhone SSH password, which you have set when you installed OpenSSH.

7. iPhoDroid will now connect to your iPhone via SSH, and execute a series of steps (15 in total) to copy all the required required files including driver files, utilities, Android image, cache, ramdisk, coresystem, userdata to install Android on your iPhone.
8. When all the copying is done, you will be asked if you like to install OpeniBoot . If you already have OpeniBoot, select the option ‘Yes, I do have’, and go to the next step.

9. When prompted to backup the NOR, select Yes only if you don’t have OpeniBoot installed yet (you have selected the option ‘No, and I want to install it’ in step 8) and go ahead.
10. Put your iPhone into scroll mode, so that you can see all the installation steps. To do this, simply hold down the Power and Home buttons till you see scrolling text. In the process, you will see the Apple logo, the recovery screen with the iTunes cable. Don’t let go off the buttons till you see some verbose mode scrolling text.
11. The Android installation will start and needs some time to be finished. Once done, you will see the message ‘iPhoDroid is done!’.

12. That’s it. The next time you start your iPhone, you can choose between booting to iPhone OS or Android OS.