In addition to multiple sign-in support, Google also introduced some new features to Gmail for mobile: users now have the ability to create a mobile signature to let people know that they’re responding from a mobile phone (in the event an email is full of typos). Users can also now set their Vacation auto-responder from their mobile phones just in case they only realize that they’ve forgotten about it while on the way to the airport.
To make use of all these features, just head over to the Gmail for mobile website. Make sure you update your bookmarks as well, because Google has updated the URLs.