The foam can come from more than just temp issues. Anything that causes turbulance in the flow will rip CO2 out of solution causing excessive foaming, so clean serving lines is important. I think it is also important to maintain as short of lines as possible, I used to have longer lines and higher serving pressure and then I played around with the calculations and temp and shortened up my serving lines and dropped my pressure around 4 psi. I also built a contraption (search around HBT and you will find a build thread on it) that consists of pvc tubing, spray foam, and copper pipe. Simply take a piece of pvc, spray it full of spray foam, and then run the copper pipe through. Put that in your tower and run the lines through the copper. Let a few inches of copper extend into the the kegerator so it can transfer the cold up the pipe and keep the lines cool. This seems to work pretty good. I get a little foaming on the first few ounces of a pour of the evening which is no big deal to me, I dump that down the sink and everything is perfect after that for the remainder of the evening. Who wants to drink beer that has been sitting in the line for a few days anyway right?