Headed to the airport? If public transportation is not an option, and if you have exhausted all the airport-ride favors owed to you, then perhaps BestParking.com could be of assistance.

The site shows the best price for parking at the airport based on your arrival and departure time. For example, the lowest price from Friday morning to Monday night was offered at the BWI Airport Long Term Parking Lots A or B. 

Now, these prices don't reflect any Internet discounts or coupons you might find on a company's Web site or elsewhere. And, you should call to confirm the rates, if they are not guaranteed. But, it's a good place to get some trip planning information.

I discovered BestParking via ShopSmart magazine, which points out that the site also compares best places to park in cities like Washington, Philadelphia and New York.