Google late Thursday rolled out Gmail Mobile, a miniaturized version of its popular Web mail service for cell phones and mobile devices. It automatically adjusts the interface depending on the size of the screen, and can even open attachments including Word documents, PDF files and pictures.

If a contact's phone number is in the Gmail address book, users can also reply to a message with a call. Gmail Mobile can be accessed free of charge by visiting m.gmail.com, but carrier data fees may apply. Google on Thursday also added two other features to Gmail: a vacation auto-responder and the ability to create contact groups.