Offline Gmail graduates
Google has “graduated” offline gmail [gmail blog]. For those users that may not always have an internet connection (commuting for instance), this option pulls a set amount of email onto the computer and allows for the system to be used while “offline”.
Once the internet connection is restored, information syncs and the system works normally. This is fantastic for people (like myself) that enjoy working with Gmail but do not want to rely on a client (e.g. outlook).
Check it out in Settings>Offline