why do I have battery, button and ac modules loaded on a desktop machine?

[Joshua Andrews]

I have found since installing that there are a lot of unused services on 
by default that really don't relate to my machine.
I don't have any wireless or bluetooth or laptop services that I need 
right away, however even after spending some time to figure out what 
some of these mysterious services related to and turning them off I am 
still seeing modules loaded, that as far as I can tell have nothing to 
do with my system, and I am not even sure where  they are being loaded from.
I mean, isn't there some way that "hal", or anaconda, can figure out 
whether I am a laptop or a desktop machine and setup the services and 
modules appropriately?