Windows Mobile users can take advantage of Yahoo Mobile: "Windows Mobile Treo users make note that Yahoo Mobile could prove a good resource for you. 'With Yahoo! Go™, your stuff is always with you and easy to use.
Click on the arrow to the right of the phone to learn more:
* Contacts — Stored phone numbers are automatically synched
* Photos — Take a picture and it’s stored online
* Messenger* — Record voice instant messages
* Mail — Get notified when new email arrives'