How to Get Bumped for Free Airline Travel

Here's How:
Ask if the flight is overbooked. Call your travel agent the night before scheduled departure.
Pack flight schedules for other airlines leaving for your destination from the departure airport.
Get to the airport 90 minutes before scheduled departure. Be first in line at check-in.
Before agreeing to be bumped, make certain the airline is offering a free ticket or a deeply-discounted ticket.
Before accepting the ticket for another day's travel, tell the agent you want to be sure of today's arrangements.
Tell the agent you want confirmed reservations on the next flight to today's destination.
If there is no guaranteed seat on the next flight, tell them you want a guaranteed flight on another airline. Cite Rule 240.
Consult the flight schedule you packed, and choose an alternate flight that works best for you.
If your wait for another flight exceeds two hours, inquire about meal vouchers and other perks.
If you get bumped from the next flight, repeat the above steps. You could get a second free ticket in one day!
These steps are adapted from Tom Parsons of Best Fares Magazine


Tips:
There are rules everyone must follow in a "bumping" situation, but some of the benefits will vary by airline.
The rules on bumping are different for international flights. Consult your airline if applicable.
Under some circumstances, the airlines have to compensate bumped passengers with cash values up to $400 USD. Don't take a ticket that's worth less if you're eligible for the money.