For those saying that getting rid of all the Dollar Bill validators would be a big cost: nope. Those DBVs are a *huge* cost for US vending compared to countries that have reasonable currency and don't need them. If you like paper money so much, why do you have quarters? As I understand it, Big Vending lobbies for the introduction of $1 coins (or more to the point, phasing out the $1 bill), because they understand that.
Quoted from Half_Life:1) $1 and $2 bills cost 5.5 cents to make; $1 coins cost 10 cents to make
$1 coins last ~25 years, $1 bills last one. Next?
Re: cheques. I have friends age about 30 in multiple countries who have never seen a cheque in their lives. Not a single one. Even your tax refund comes as a bank transfer.