If you get a big enough compact flash card then you can install OS 9 on the flash card and then with the card adaptor you can run the computer with some games on the card without using your internal hard drive, That should give you a lot of battery hours.
Check out the "Energy Saver" portion of the System Preferences. There's an option for "DVD Viewing" (or something like that) for optimum battery life. But I haven't used it much. When I travel now, its always by train and Via 1 has electrical plugs for computers in the seats. When I had my Lombard, the DVD decoding was done in hardware and you could spin down the hard drive and set the performance to 'long' (or whatever that was) and you got amazing life out of the battery.
Games, you might want to turn off sound, that'll help, but not much (especially if you need to hear bullets bouncing off your armor).
Of course, the 'pay for' answer is an extra battery...
Thanks dolawren. Another way to do that is to make a RAM disk in OS 9 and them boot off the RAM disk. That tip is from our friend David Pouge, he reported an 8-10 hours average with one battery on his Pismo.
Does anyone know of a way to rip a DVD to the harddrive? Or will running the DVD-ROM take less power. I must watch the Matrix atleast 2 times before the next movie comes out.
See the F1/F2 keys with the little suns on them? Use them to decrease the brightness of our screen. For genereal work, having only 3 or four of the little bars on the readout is enough to still see alright. For DVDs, half brightness is still alright, but check it out before you leave to see what you can tolerate. The backlight of your LCD is the single biggest battery killer.
In energy saver, under the Options tab, Processor performance: Reduced.
Also, Under the leep tab, use a separate (shorter) time for display sleep, and let the hard drive spin down when it can.