i would just like to add from a UK point of view that using resistors directly on the mains supply is a very dangerous thing to do because effectively your pic circuit will have potentially 'live' parts that have no isolation from the power line.
also dwane, you say the voltage will vary when an appliance is turned on, yes it will but only by mili volts, in the UK we have a tolerance of 4% for voltdrop in an electrical system, so if the voltage is dropping beyond this then there could quite possabily be a problem in the mains supply. another thing to consider is large current drawing appliances such as tumble dryers/ electric heaters/ fridges will cause surges and spikes on the mains when switching in and out. if you do not have sufficient protection to snubb these surges and by using just resistor voltage deviders straight into the pics then they are just going to go pop! the other thing that you have demonstrated for example the 1/12 ratio and getting 4.5 volts out after silicone rectification for 120 volts then this doesn't really give enough resolution of scope to measure small varying changes surely?!