Summer could be a bummer. Travelers will face record crowds in airports and hotels, not to mention at rental-car counters. Procrastinators will find soaring fares and short supply. Here are some of the potential vacation unpleasantries that await--with advice on how to minimize your pain.

I haven't even booked an airline ticket yet. Am I out of luck?

Hardly. Two new websites, Farecast.comand Farecompare.com, promise to take some of the guesswork out of finding an inexpensive flight. Farecompare, launched earlier this summer, lets you look at historical airfares to determine whether prices are likely to rise or fall on a route. Farecast also displays historical fares in limited markets and predicts future prices, too.

I've been bumped from my flight. What now?

Your airline is going to try to make you an offer--probably a seat on the next flight and a voucher for a couple hundred bucks. Whether you volunteered to be bumped or not, hang on. Read your airline's contract of carriage--the legal agreement between you and the carrier--on its website. (If you don't travel with a laptop, print it out before you leave home.) You may be entitled to a better deal or more compensation. For example, an involuntary bump usually entitles you to cold cash, not airline funny money. Peruse the fine print (normally Rule 245) before accepting anything.

I'm afraid I'll be stuck in a long security line and miss my flight.

That's a valid concern. Consult your airline's website about check-in times. To boost on-time arrivals and departures, some carriers now require you to check in 90 minutes or more before departure and close the gate 15 minutes before takeoff. In this busy summer, you may want to arrive even earlier. If you are truly line-phobic (and a fairly frequent traveler), you can skip the line entirely at certain airports. An $80-a-year membership in the Clear Register Traveler program lets you shortcut the normal security line by getting prescreened, then using a card and fingerprint and iris scanner to verify your identity. Currently in Orlando, the service plans to expand to several airports this summer, despite criticism that it is unfair. Details are at flyclear.com.

Help! There's no room at the inn.

Even though 2005 was the most profitable year ever for the hotel industry, the average occupancy rate was just 63 percent. So chances are, you'll find a room somewhere, even at crowded destinations. Try websites that deal with last-minute hotel inventory (Priceline.com and Hotwire.com). If there's a room to be had, they'll have it. Also, check out two new sites, homeAway.com and forGetaway.com, which specialize in vacation rentals that run a fraction of the cost of a hotel room.

They're out of my rental-car size. Do I have to pay for a bigger car?

This is a common summer problem: A rental company runs out of cheap subcompacts and gives customers a choice: Either wait several hours for someone to bring back a matchbox car or pay for a pricey upgrade. The best solution, when presented with such a dilemma, is to call the corporate office. Most reputable car-rental companies are supposed to offer a free upgrade to the next class of car when the vehicle you reserved isn't available.