Instead of using change at the parking meters on the street and in garages in Bethesda, MD you can now register at ParkNow and then call a phone number, enter you space (or location) number and the amount of time you want.
This convenience comes at a price though, in addition to the standard meter payment they charge 25 cents per transaction.
How to use it:
Depending on what meter you are at, there will either be a "space number" (like the picture above) or a "Location #"
This sign at the entrance to Elm St garage says that it will save you money, but since they charge per transaction and you don't get a discount on the meter, I'm not sure how you save. If they would add time to the meter a nickel at a time until you called and canceled or if you could call before the meter was active in the morning then not start charging until it became active then I could see it saving money. I don't see how it is faster than putting change in either, although the convenience of not having to keep change in your car is a plus.
Update January 30:
As one person mentioned in the comments, this is currently limited to Bethesda Ave, Woodmont Ave near Bethesda Row, and Elm St. plus Garage 57 and the large surface lot across from the book store (Lot 31). According to DOT, this is just a test and it only runs through April 4th, after which the meters will no longer accept cell phone payments. Depending on how the test goes and what is approved in the budget, they may decide to get bids to do this over a wider area.