My notebook gets ridiculously hot.  I cut some holes in my desk to get 
some air circulating under it.  I'd like to attach a few small fans to 
move a little more air, and some fans from a PC case seem ideal for both 
size and noise reasons.

I know nearly nothing about hardware.  I think I can hook these up to a 
PC power supply, and plug the power supply into my wall, right?

Questions :
  - Any better ideas for small quiet fans which could easily be attached 
to a desk?
  - Is it safe to have a PC power supply outside of a case?
  - Where can I get a cheap power supply?  To run a few fans, I'd think 
any piece of junk ought to do.  Frys?
  - Will there be any way to switch this rig on/off besides just yanking 
out the power cord?

The safety issue is the primary one.  I have 2 little kids, and while 
they aren't allowed in my office, I don't want a potential electrocution 
hazard anywhere in the house.

thanks,
alex