Roach control:

Distribute containers containing equal parts confectioners sugar and
baking powder (baking soda could be substituted) around area where
roaches are a problem - 

They will be attracted to the sugar and ingest it along with the baking powder;
later as the baking powder mixes with body fluids and outgases CO2 their 
bodies will explode. Lone roaches finding the mixture and coating their bodies with it
will carry it back to the roach colony, which through their habit of preening one another
will distribute a deadly dose to many more roaches.