In response to mjg59's rant about controlling the LCD brightness on laptops, I invested some time to reverse engineer the Windows driver of my MSI S270 laptop which implements changing LCD brightness. It requires some ugly fiddling with registers of the "embedded controller" on ports 0x62 and 0x66. The result of my work is s270ctrl, a small userspace utility. I'm planning to turn this into a proper kernel module soon.