The latest online app to help drivers track fuel economy comes from Moblu. The site asks for your vehicle’s year, make and model then requires you to create a user name and password.

Where, you might be asking, does the social networking come in? Moblu uses your Twitter user name (no Twitter password required) to share your mileage with other Tweeple. Moblu users can record events that might affect gas mileage, like “Changed Tire Pressure” or “Lots of Highway Driving.” You can also record a fill-up, calculate mileage for a road trip, and find fellow Moblu users on the site.

Clicking on “My Garage” shows fellow Moblu cars, with actual mileage, trends, and number of fill-ups. You can choose to follow anyone who looks interesting, or keep tabs on your friends’ fuel economy.

After a disastrous second quarter, Ford announced that they’re going to build fewer trucks and SUVs and import six small cars that the company’s been selling in Europe. Consumers, and the dealers who can’t move SUVs off their lots, are chomping at the bit to get these more fuel-efficient vehicles.

The Ford Focus and Fiesta sedans and hatchbacks currently on the streets of Paris and London will be available in the U.S. in 2009-2010. At the same time, three truck plants — two in the U.S. and one in Mexico — will switch over to building the small cars that are currently in such short supply. I can’t help but think that a little bit of foresight on Ford’s part could have saved them from their worst quarter ever, which just ended with a total loss of $8.7 billion.

If we’re lucky, we Americans will get the latest Fiesta, the ECOnetic, which debuted in London July 22. It gets the best fuel economy in the company at 3.7 l/100 km, which on this side of the pond is an amazing 63.5 mpg. It also has the lowest CO2 output in its class, at 98g/km, yet it still has a top speed of 110 mph.