Homebrew PCBs

DJ,

Your site mentions making four layer boards.  How do you make them?  Are
they two two layer boards glued together?  How do you handle vias?  

"The test board is a four-layer board because it vastly simplifies the power
system, and I can make them at home as long as they're not too complex."

http://www.delorie.com/electronics/sdram/

Jeff