This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Linux certifications are mainly for sysadmins. There's no Linux certification I know of that addresses Linux programming, in part because relatively little programming is Linux-specific, especially in Java.
Customer surveys are for companies who didn't pay proper attention to begin with.