If you use a mobile device with the Microsoft Windows Mobile 6 Professional operating system, you can view your Picasa Web Albums photos offline with Google Gears, a browser extension that allows web applications to provide offline functionality.

To get started, you'll need to download Google Gears, to your phone. After installing Google Gears, follow these steps to add offline functionality to your Picasa Web Albums photos:

Sign in to Picasa Web Albums at http://picasaweb.google.com/m
Scroll to the bottom of the window and select Make photos available offline (beta).
After the screen refreshes, select the checkbox(es) next to the album(s) you'd like to view offline.
Click Go in the upper-right corner of the window. A status bar appears. Once the process is complete, a small green icon in the shape of a phone appears next to the albums that you can view offline.