Adding/changing the Google homepage background image

1. Sign in to your Google Account in the top right corner of the Google homepage.
2. Click Change background image at the bottom of the Google homepage.
3. Choose where to select your background image (Public gallery, from your computer, your Picasa Web photos, your recent picks, no background)
4. Once you've chosen your image, click Select at the bottom of the window. It may take a moment before your new Google homepage background appears.