How to travel with an electronic ticket
Electronic tickets (or e-tickets) allow both Yahoo! Travel and the airline you're flying to store your ticket on our respective computer systems. You don't have to worry about carrying or possibly losing your tickets. No paper document is issued until you check in with the airline.
While it's a good idea to bring a copy of your e-ticket receipt with you on your day of travel, it's not required to have a receipt to check in. You need your proper identification (government issued photo ID—driver's license or state identification card) for all travelers.
The Transportation Security Administration has enacted a policy at most airports that requires all passengers, including e-ticket holders, to obtain a boarding pass (obtained at the airline check-in counter or airline kiosk if available) before entering any security checkpoint that leads to a flight gate.