Guests are growing more and more tired of waiting in lines for amusement park attractions. There is no way to replace standby lines without going to a completely digital system. With thousands of visitors everyday a digital system would grow very large and extremely complex. The best parks can do for now is improve their current standby lines. Think outside the box. Offer more entertainment and most importantly things to do while waiting for their favorite attraction.
I've heard good things about the Revenge of the Mummy queue at Universal, and of course Disney is a leader with Mr Potato Head/Buzz Light Year animatronics giving a show for the kids in line. But there needs to be more, something for the guests to actually DO. My first and simplistic idea would be like one of the those handheld trivia games you can get at Buffalo Wild Wings. TV monitors would show who has the highest score, maybe that person gets to skip ahead inline or is entered to win free park tickets for next day.