There is that nifty wristwatch one that uses your finger to transmit and recive sounds.
I have had a phone since i was eleven and i have it with me maybe 3 days a week if i remeber when i was at school i only carried it on trips or if i thought i would stay late some times i would chuck it in the bottom of my bag until it woud run out of charge and i would get round to charging it
.All my phones have been very simple affairs my first was a "cooncil brick" and my second a siemens one that got stolen and the third a motorola flipy dealy before colour screens and that stuff still have it still works no reaon to get rid of it really: it is getting a bit worse for wear so i was thinking of a new one for christmas something that looks nice for a change, but i probably wont im far to stingy to be honest(complete stereotypical scottish person in that respect if i could bury my money in its box i would.)
. I dont need features though now(they are nice but not all to much point to java games) and i certainly didnt when i was younger i dont text its a stupid waste of money and i dont play games i dont really make phone calls due to my dislike of talking on the phone. So if you have a child that is vaguely responsible or like me doesnt like phones just get them one, you can always take it off them, its a parents perogative. ( i wonder where all that stuff goes it jus disappears they swear they gave it back and you are sure they didnt, ah the memories.
Also considering the price of a mobile, at a birthday it is more and more common to just get money it would be pretty easy for them to just go and buy one themselves, i have had to buy my mobiles that way.
Or like dsnette said fit them with a gps device, one fo the ones from fortress so that you can "INTESTINATE" them when they annoy you and do the bad things. A much more politically correct way to punish a child than a smack round the lugs(not that that did anyone any harm)