How can I radically mimimize power usage when I need to conserve battery?

view full story

http://askubuntu.com – I often work from locations where I don't have a way to plug in my laptop and I need to get some single thing done. I'm looking for some good strategies that I could use to shut off all the processes I don't need (local Apache server, mysql and postgres) when I know I won't have a way to plug in for a while, but restore them when I do have power and would prefer to have my full development environment available. How do other people manage this? Do background database servers use enough power for this to be worth doing? I've got a Thinkpad x301, running 11.10. If that makes any difference. (HowTos)