How can I control the brightness from the notification bar? My friend has the Galaxy S and is able to control the brightness by sliding his finger over the notification-bar. He said he didn't install anything to have it (but he has a custom ROM, so that doesn't have to mean anything).

I have the HTC Desire running with the Cyanogen MOD. I tried finding a widget or something else that will allow me to control the brightness from the notification bar, but came up with nothing.

Can it be done?
This is an undocumented feature in certain Samsung devices. Hold your finger over the notification bar and then sliding it left and right can increase/decrease brightness.

It started with the Galaxy S, IIRC. Also, "auto-brightness" setting must be turned off.