Physics students are remarkably resourceful, and over the years several web forums have developed devoted to studying for the Physics GRE. Here are some of our favorites:
physicsgre.com - A forum for prospective grad students discussing anything and everything about the test, grad school admissions, and life in physics.
grephysics.net - A complete list of the problems from the four ETS-released exams up to 2001, along with student-contributed solutions.
ETS Physics GRE page - The “Practice Booklet” provided at the top of the page contains the most recently released sample exam, from 2008.
Physics: A Student Companion - Also recommended as a nice, broad summary of physics, geared for students who are preparing for exams.
Resources from Conquering the Physics GRE - Here's our list of subject-specific books that we found useful when preparing for the exam.