The official google blog posted an article about 10 “little known” gmail features.

Most tips are quite unusual for most people I guess but most of them could be used efficiently.

The 10-6 tips are here: 10-6
The 1-5 tips are here: 1-5

The number one tip were a “Create event” function, the second tip was “offline chat”, and the third was “advanced search”. Three great functions I’ve never used.

Could be useful for somebody atleast!