turning off (LCD+) backlight without suspending

[Tony Godshall <togo@of.net>]

Anyone know if there's a tool to turn off the backlight or
the video subsystem without turning putting the whole laptop.
I like to start some mp3's playing and then shut the case.
I'd like the battery to last as long as possible in this
mode and not get so warm in my backpack (biking home from
the office or walking through an airport).  

((The computer in question is an HP Omnibook 800 with P166, 
48M RAM and a 20G hard drive running debian (woody/frozen) 
and kernel 2.4.6 and XFree86 4.0.3.  Thank godness it
doesn't have a case-close suspend feature or I couldn't do
this at all))

Thanks in advance for any solutions or even hints on which
FM to R ;P  You'll save me the cost of an MP3 player ((have
you seen the price of a model with enough capacity to hold
even a couple albums?  Yikes! ))

--
Tony