Apple has an app called iCBET which is a collection of questions in many subject areas. The complete package costs about $10 but gives a lot of sample questions.
CABMET (Colorado Biomedical Association) offers a training/review class several times a year. They have a very high pass rate. Visit their website to learn more. ( www.cabmet.org
AAMI has a review CD. Visit them at www,AAMI.org
to see more.
RSTI offers some review/study material, www.rsti-training.com