There are plenty of games that can not only help kids grow more comfortable with the alphabet, but also help them pass the time. One way is to take turns watching signs, license plates and other roadside lettering for each letter of the alphabet. The game can slow when tough letters come up, but eventually even a Q crosses the horizon.
Another game involving the alphabet is one that can get kids thinking about all kinds of topics, from animals to countries to kinds of food. Again taking turns, go through the alphabet thinking of an example of whatever topic you've chosen for each letter.
If you're looking to build a little vocabulary, another way to play around with license plates is to challenge children to make words out of the letters on each one. UIN, for example, could be unicorn, unite or interrupt. You can use variations of these games for different aged players.