Oil has never cost $110 a barrel before, and fuel now eclipses labor as the airlines' largest expense category. Recession in the early 1990s and in 2000-2001 drove numerous carriers into bankruptcy, but not four companies in less than two weeks. Basic fares on major carriers, while still lower on an inflation-adjusted basis than they were before deregulation in 1979, went up last week for the seventh time this year as airlines try to cope with the fuel costs.

What's more, customers say the service at many airlines is bad and getting worse - and that was before the waves of recent flight cancellations to make sure carriers are following all aircraft-maintenance regulations.

The Federal Aviation Administration and some airlines are making many travelers nervous, leaving them to wonder what other rules may have been violated.

So what are people who must travel for business or want to keep doing it for fun supposed to do now?

A big chunk of the national and global economy depends on your continuing to fly - and that creates light at the end of this particularly dark tunnel.

As long as we can afford to fly, we will, and that means we'll give the airlines enough business for them to survive this rough patch. Most of them have ample cash on hand. Fuel costs them more than labor today because bankruptcies and the last recession enabled them to cut many employees' pay, saving them billions.

But you can make a difference in which airlines thrive by giving your business to those that have given you the best service, at a reasonable price, in the past.

You can see who's on top overall, based on on-time performance and fewest lost bags, complaints and bumped passengers, by looking at the Airline Quality Rating at http://www.aqr.aero/.

In the meantime, watch for airlines planning mergers or closer cooperation through joint marketing and service agreements. Such combinations are likely to be better for investors and senior executives of the merging airlines than they are for employees who could lose jobs and customers who may see less competition. And if you wind up on one of the mega-carriers that comes out of a merger and it doesn't deliver the service promised, don't use it again.

You also may try political pressure, telling your congressional representatives that you want to see tax dollars spent on the FAA hiring more maintenance inspectors and air-traffic controllers and investing in the next generation of air-traffic technology. Tell lawmakers to get moving on reauthorizing the FAA in a way that gives it adequate resources while also trying to make it less of a sluggish bureaucracy.

The recent spate of canceled flights also has revived talk in Washington of a passengers' bill of rights, requiring carriers to provide food, water and working toilets during long on-the-ground delays. That wouldn't have helped you if your flight was canceled in recent weeks, but just the threat of legislation may inspire airlines to set higher standards for service.

(Find a link to that story and other topics here at http://blogs.phillynews.com/inquirer/roadwarrior/)

Now it's your turn. We posted a story on the Road Warrior blog last week about a European Union decision allowing airlines to offer a service that lets passengers use cell phones during flights.

In this country, federal regulators last year reviewed the ban on cell phones in flight and decided to keep it because of both public opposition and lingering questions on whether it could interfere with aircraft navigational equipment.

Flight attendants in particular oppose lifting the ban out of concern that they will have to deal with more instances of air rage when one passenger tries to stop another from yakking away.

So tell us what you think about using cell phones in flight and whether the ban should be kept. E-mail is the best way to reach us.