You may not have realized you could bring a bottled drink onboard. You can — if you buy it after you go through security. Screeners limit the size of liquids you can bring through checkpoints.

That’s just one of many options to make air travel more comfortable.

Here are others:

• Airport VIP lounges are not restricted to members. Several airlines offer one-day or monthly passes. If your flight is delayed and you have a long wait, check out one of the lounges, which offer a comfortable atmosphere, Internet access, drinks and snacks.

• Don’t pay a checked bag fee for strollers and infant car seats. Airline personnel will put those items on the plane for you for free when you get to your gate, and they will not count against your carryon bag allowance.

• You don’t have to pay big bucks to fly in business class. Several airlines offer deeply discounted rates on upgrades to business class on the day of travel. Members of airline frequent-flier programs can use miles or flight credits to upgrade from coach to business class.

• You don’t have to pay big bucks to fly, period. Rick Seaney of FareCompare.com says the best time to shop domestic tickets is Tuesday afternoon. Airlines typically file sales Monday evening, and other airlines match Tuesday through noon. "Be wary of shopping on the weekends," Seaney says. "Most discounted airfares expire or are removed from the reservation systems on Friday, leaving higher prices in the system over the weekend."

• Don’t worry about printing out your boarding pass at home. At some airports and with some airlines, travelers with Web-enabled mobile devices like a BlackBerry or iPhone can download their boarding passes, then hand over the devices for scanning by federal security screeners and airline gate agents. Continental Airlines spokeswoman Mary Clark says the carrier offers the mobile boarding pass option at 28 airports, including ones in Houston and Newark, N.J. Even if that isn’t available at your airport or with your airline, at many airports you can print out your boarding pass quickly at a self-service kiosk in the terminal. You can generally find out if your airline offers the mobile boarding pass option and at which airports the carrier offers self-service kiosks from the airline’s Web site.

• Traveling doesn’t have to be a hassle. If you fly at off-peak times like in the early morning hours or on Tuesdays, Wednesdays or Saturdays, flights are less full, and often the lines at security are much shorter. Many smaller airports are rarely congested at all, says aviation consultant Mark Kiefer of CRA International in Boston.

• Speeding through security is easy if you pack certain items in your carryon bags before reaching a checkpoint. Alaska Airlines’ in-flight training manager stores his belt and small wallet in his briefcase. He no longer carries a laptop, just memory sticks. Often, he does not even need a tub when traveling without liquids; He stores metal items in his briefcase.