Yup, I cheated on Wroclaw's University of Technology which is pretty hard, they block cellphones etc, so I had to resort to equipment from www.gsm-earpiece.com, I just put pre recorded files on my mp3, and liestened to them during the exam, the earpiece is really smal so its really hard for someone to notice you have something in your ear. Depends on your ear anathomy somewhat too i guess.