If you haven't booked your reservation ahead of time, don't despair. Frequently counter agents are empowered to cut last minute deals to get your business.

Compact and subcompact cars are cheapest, so they're the first to get rented. Whether these cars are right for your vacation (i.e., with all that luggage and those kids) is something you and your therapist have to decide.

Savings tip: Chances are if your auto insurance has comprehensive coverage (collision and liability) you won't have to spring for it at the rental counter. Check with your insurance company.

Think about renting a used car from a company like Rent-A-Wreck. According to some sources you can save up to 66 percent on your car rental bill. Just be sure to take it for a test drive before committing.

Hey Mr. Bus Driver!:
If you let the bus driver do all the driving, you'll save on gas, wear and tear on your car, you'll get to enjoy the scenery, read that book you've been meaning to and, oh yeah, not fall asleep at the wheel. On some routes you can save as much as 85 percent over flying.

Derailing Your Train of Thought:
Think about training to your location. The view from a train is usually majestic, and the best part is you don't have to drive. The romance of the rails is alive and well. If your trip is over a six-hour drive, you're probably better off on the train.

Trains cost a little more than the bus, but you get to stretch your legs more and they often have an onboard dining car. If you travel on a train during the winter you will probably save around 15 percent (it is also generally safer and less likely to stop because of road conditions). Check out the excursion rates, which can offer 20 percent discounts with certain restrictions. Contact AMTRAK and check out their "All Aboard" program, which allows travelers to stop three times along their route. After you are done sightseeing, you just catch the next train. The tickets are good for 45 days so you can stay at each of the towns for 15 days. 

If it takes more than a day traveling by ground you should probably hop on a plane.