I wouldn't recommend a powder extinguisher for use in the home. Yes, it puts out the fire, but it also causes alot of collateral damage because of the salt crystals in the powder - they can cause problems with electronics (TV, video, DVD, stereo, computers, and anywhere else you have a circuit board). I have a "light water" extinguisher (water with a bit of soap to reduce surface tension) for most situations, plus a fire blanket for putting out fat/oil fires.

Just my $0.02