Here is my robotic arm made of 4mm hardboard with a 3-axis cnc, it is also printable. The servos are the most cheapest ones (TopLine standard servo RS 2 J/R and TopLine mini-servo ES-05 JR).
A little video:http://www.youtube.com/watch?v=gfsLu1iuLRg
More about the electronics and other info at:jjshortcut.wordpress.com/2010/08/17/multiply-the-robotic-arm-and-electronics/
About the mechanics: jjshortcut.wordpress.com/2010/04/19/my-mini-servo-grippers-and-completed-robotic-arm/