Physics for the IB Diploma: Study Guide - If your taking the exams you should have this book. It's not a textbook, but it may be hands down the best thing to help you review. This link is for the "new syllabus" or in other words for exam in 2009 and beyond.
Online Paper 1 Questions - Created by Chris Hamper, looks mighty useful for reviewing....
Chris Hamper's Site - My IB trainer and he knows his stuff. He has labs ideas and much more. Good stuff. His blog says he's writing a book... maybe there will be an IB textbook worth buying?
IB Physics SL Book - Might it be worth reading? Chris Hamper is a co-Author so the answer is a definite maybe (and probably yes). I personally have not seen a copy.
Physics Daily - an enclopedia of sorts
Physics Classroom - good source for introductory ideas
A-Level Site - based on the british A Levels but has a lot that is useful for the IB
HyperPhysics - This site has everything! If you can't find it here you aren't looking hard enough.
Physics Simulations (PhET) - Incredible site
Top Mark on CE - written by a friend, for the old (2008) syllabus but still good.
IB Lab Guide - Written by me a outline for how to write a IB lab.
How to Write a Method - Some of my kids wrote 3 page methods, I tried to simplify it for them
Worsley School
Reading for the students (stuff that was easier for them to read then for me to spend a class or more just talking):
Michelson Morely Experiment Interferometer
Gravitational Lensing Red Shift