Thriftyapp

Search for flights on Momondo’s search engine which also includes high speed trains in Europe.

In addition to calculating the cost of gas, mOblu works for other modes of transportation from scooter to train.

Mobissimo claims to be the world’s most comprehensive travel search engine identifying the standard travel, flight, hotel, and car rental deals.

Side Step offers cheap flights, hotels, airline tickets, and travel deals by comparing hundreds of travel site offers.

Hat tip NYT.

The bus fares are competitive with other similar bus services like Bolt and Mega

Fares from $1 in cities from Baltimore to Boston and DC on Bolt Bus.

Mega Bus is a “low cost daily express bus service in the US and Canada.

Washington Deluxe is a low cost bus service from NYC to DC and DC to NYC.

Bus Junction is a great site that compares bus fares.