I'm in Middle School(not telling which grade, cus it doesn't even matter!). Anyway, we girls hide it in our purses.
My homeroom and social studies teacher has banned them, but my English teacher told us we could play with them when we are done with our work(She's real nice), and my Math and Science teachers don't really care. Just remember, like everyone else said, sound OFF! The clock thing doesn't work cus my teachers know what they are. If you are a boy, hide it in a jacket pocket.
Also, more tips:
ALWAYS keep it with you, if you let your friends play with it, they might expose it accidentally.
Sometimes, if I have a bad vibe about that day(lol), I leave them @ home and change the time to their bedtime. Also, if you do not have anything to conceal your tama, hide it in your shoe. That's what I did on Monday. I slid both tamas in the side of each wallabie, and it worked! I did that because I thought there was going to be an iPod, cell phone, and tamagotchi check that day.
Also, for Middle-Schoolers and High-Schoolers, if you play an instrument, you can hide it in that case. People hide their tamas in the cases all the time @ my skool. If you have a binder, that will work well, too.
We play with them in the bathroom and at lunch, plus bathroom breaks.
And you guys: PLEASE, PLEASE don't put your house key on your tamagotchi ring!!! My friend lost her tamagotchi, which means she lost her house key.
Hope this helps.
^_^ *~Ally~*