Finally!!!
The Internet Message Access Protocol is an application layer Internet protocol operating on port 143 that allows a local client to access e-mail on a remote server. The biggest advantage of IMAP is that you can check your email on your iPhone and when you go home after work, you will see the same message on your desktop but with the exception that they will be already read. Basically, you don’t have to read the message twice. Ain’t that nice? Productive! There has been some work around on the net for a long time but, now, it’s available and it’s free.
IMAP @ Wikipedia
GMail Blog