The bother of waiting around for a check, or struggling to figure out how much everyone owes, is a thing of the past. With mobile-payment apps, you can now pay your dinner bill (or, even more conveniently, bar tab) and calculate tip, all from your smartphone. (free, iOS and Android) currently works in 5,000 restaurants in major markets all over the country.
PS: Even if paying the traditional way by credit card, one need not wait for the check to arrive before submitting one's card. Time can be saved by handing the server the card before the check arrives, which saves the server a trip and saves the diners time. Nor is there any worry about any errors in the check because you can look at the check for accuracy before signing the receipt. While this time-saving approach might save just a minute or two for any one meal, over a lifetime, the time savings can be huge.