What do you mean direct from the desktop? Do you mean know when you have new messages? You could use the POP functionality in Gmail to forward it to outlook and set that to run on startup in the system tray. Or download the google talk app which will allow you to see a notification in the system tray if you have new messages.
The latter is quite useful and I use it myself. However If thats not the kind of thing you are looking for let us know a bit more detail as to what exactly you need and we will see what we can find.