What kind of charms (example-cell phone/iPod case, keychain etc.) you want a company to manufacture for you?

I am asking this question as part of a youth project in Junior Achievement of Canada. Based on popular consent, we are actually going to manufacture a charm (which we are hoping to be either a cell phone/ipod case or keychain) and then we will sell it in our school and local market. So, we want to know what you think us to make for you, with what design imprinted/craved on it and every possible details you want us to care about. We are also hoping that you will tell us how much money you are willing to spend on that item (for example: 2-5 dollars or so). Our price range for selling would be in the range of $4-10. But we will try to give it to you on the price you want. So, please tell us how much in maximum you will pay for it..Thanks!!!