"How to Install .Apk Apps on Google Android G1 Phone
1. Install and open the Apps Installer application from the Android Market.
2. This opens a view showing *.apk application names in the sdcard root directory.(note, if no AppNames are listed you have no .apk files in the root directory of the SDCard)
3. Touch the app name to initiate installation of the app.
4. The app is now installed
How to Non-Market .Apk Application on Google Android G1 Phone
1. Download and install Google Android SDK.
2. Now type adb in a command shell will display all the options, adb.exe is SDK tool used to install applications and interface with the device.
3. Now Connect Your G1 Phone to your computer using USB cable. You need to install Drivers for this. Download Android USB drivers from here. This driver is required for adb to interface with an android G1 phone using USB cable.
4. Go to Android Settings/SD card & phone storage and disable Use for USB storage. You can enable it again later after you installed your third-party application.
5. Go to Settings/Application settings and enable Unknown sources.
6. Download the Application installer .apk file to a local folder on your computer, Now type below command at command shell to install app.
The above guide is only application for windows XP users and Windows Vista users wont be able to use it, since android sdk for windows vista is not available." blogsdna.com