When they were first introduced in 1994 by Southwest Airlines, paperless or electronic tickets were resisted by the flying public.

Passengers professed to want the comfort of holding "real" tickets, those booklets of stapled flight coupons that are now rarer than a hot meal in coach. As late as 1997, only 10 percent of airline travelers used e-tickets. No longer.

By the end of 2005, most domestic airlines had phased out paper tickets entirely, and most have coordinated with overseas partners and other carriers to implement electronic interlining, which permits totally ticketless, seamless travel on worldwide itineraries.

The carriers' gradual but purposeful move from travel agent to direct purchase, and from paper to paperless tickets, was propelled by the expectation of huge savings in distribution costs, in revenue accounting and billing, and in handling costs — which were adding $6 to $8 per ticket. The cost benefits have proved so significant to America's carriers that they typically charge a fee (actually a penalty) of $10 to $25 to issue paper tickets at a customer's request.

An electronic ticket works like this: A passenger reservation is originated — by phone, in person or online — in an airline or travel agency computer; credit-card data is input; and seats may be selected. The traveler is then faxed, e-mailed or handed a receipt, an ordinary sheet of paper, which indicates the passenger's name, record locator (airline confirmation number), itinerary, fare, method of payment and ticket number. That's it.

That paper receipt constitutes your entire "ticket."

In the wake of the 9/11 attacks, the FAA introduced regulations that allow only ticketed passengers beyond security checkpoints. So bring your printed receipt to the airport, along with a government-issued picture ID, such as a driver's license or passport.

For extra reassurance, also carry the credit card you used to purchase the e-ticket. (You might need it to use e-ticket kiosks, or you may be asked to present it at check-in.) The airport counter clerk will review your reservation in the computer, then issue a standard paper boarding pass for the flight.

With an e-ticket, there's nothing to lose or for thieves to steal. The airlines state that if the passenger fails to appear with his confirmation receipt, they can reconstruct a record using only the passenger's name, credit-card number and destination.

Once the booking and payment are confirmed in the computer, a new receipt and a boarding pass are issued. Electronic tickets eliminate the aggravation and expense of re-issuing missing tickets and of costly overnight emergency delivery services.

And do-it-yourself bookings are easy. Make a reservation online, pay by charge card, then print out the confirmation receipt. Over. Done.

You also can easily purchase tickets for other people who live in different locations, and simply forward to them by e-mail the online receipt you receive. I do this frequently to fly family and friends to Hawai'i on mileage-award tickets.

One of the advantages of purchasing your e-tickets through the Web is online check-in, typically permitted 24 hours or less before departure. You can print out your own boarding passes, with barcodes, that permit you to skip airport check-in entirely if you have no luggage. The gate attendant will swipe the pass over that machine with the red laser light, and you're good to go onboard.

Even if you can't manage to check in online, self-service kiosks at many domestic airports allow an e-ticket holder to bypass long check-in lines. Insert the credit card used to purchase your ticket and receive a boarding pass plus printed receipt. Head directly through security to your gate. Check with individual airlines regarding availability of kiosks at your departure airport.

Despite the convenience of purchase and protection from theft, there is at least one caveat a consumer should observe when using an e-ticket. Where paper tickets included reams of "fine print" regarding baggage liability, cancellation and change restrictions, and other policies, an e-ticket may not offer any such references. Be sure to inquire before purchase about the "what ifs" that are important to you. Rarely are coach tickets — or even discounted first-class tickets — refundable, and even minor itinerary amendments may add heavy penalties that masquerade as service fees.

Consumers, encountering a flight cancellation, delay or a personal emergency, used to be required to convert from paperless to paper tickets before obtaining passage on a substitute carrier. In most cases, this inconvenience has been eliminated, with domestic and international carriers cooperating to address luggage handling, ticket endorsability and other policies on passengers. The scope of these arrangements between one carrier and another may vary, so check with the booking airline before ticketing.

New advances in intra-airline connectivity are taking place at a lightning pace. The paperless future is now.

Irene Croft Jr. of Kailua, Kona, is a travel writer and 40-year veteran globetrotter. Her column is published in this section every other week.