Unlike on the desktop, where the feature relies on extensions, offline Gmail for mobiles is dependent on HTML5s AppCache and database standards to keep data available when there is no internet connection, meaning it requires no additional software downloads. It also means that the feature would work flawlessly across multiple operating systems just as long as they support HTML5.
Aside from offline Gmail, the search giant also showed off an HTML5 built browser version of Google Maps on the Palm Pre which offered all the functionality of a native client. Theres no word yet on when Google will widely release these new features but things are certainly looking interesting in the mobile scene, with HTML5 providing an easy way to bring projects to multiple devices without the need to re-code the app for each individual platform. Videos for both demonstrations are available after the jump.