twistedumbrella from xda has compiled the steps that can install ubuntu on any Android mobile phone. The steps have been tested successfully for Thunderbolt, Droid, and Droid2 etc.

Other methods to install this OS on Android smartphones,
• Booting on DHD
• Installing Ubuntu0.3 on HD2

You can follow the below easy steps for installation:
1. Create a folder on SD card by the name ext2ubuntu, which is /sdcard/ext2ubuntu and when listed in adb or terminal window.

2. Download sh file

3. Download img and put it in the /sdcard/ext2ubuntu

4. Make sure that you have an ubuntu pc.

5. For adding ext2 partition with your desired size to the SD card, use the gparted. You can try the default 4GB if you want.

6. Ubuntu – Get gparted in the synaptics or in the terminal and enter the below code:
sudo apt-get install gparted

7. Use adb for running /sdcard/ext2ubuntu/ubuntu.sh
Code:

adb shell
su
sh /sdcard/ext2ubuntu/ubuntu.sh

or from terminal

su
bash /sdcard/ext2ubuntu/ubuntu.sh

Please make sure that only some of the ROMs support this.

8. Open the terminal window and enter the ‘bootubuntu’ for testing the installation.

The scripts will be downloaded and installed automatically now. The scripts have an auto-update function by default, which means that the required scripts would be updated automatically.

A new SD card direct option was added that allows the user for replacing the scripts (those are installed) with command ‘ubuntu’ which helps in running the scripts from sd-card directly. This option helps users for replacing the files in /sdcard/ext2ubuntu with the new versions.

If you see a localhost prompt then you need to perform some more steps

If you want that your ubuntu apps install by own then please make sure to enter below commands:

su
backubuntu
4

If you want to view the Ubuntu-Desktop then you need a VNC Viewer (ex: Android Vnc Viewer) for Android.

Please note the below fields:
Address: 127.0.0.1
Port : 5901
The pass-word is tightvncserver one that you set.

Now you can use Synaptics and download the eclipse there.
You can also download eclipse from localhost prompt with below command:

apt-get install eclipse

You should also get android-sdk. After getting it on your computer, type command as below:

tools/android update sdk -u -s

All supports at xda link