"With a cell phone or an Internet connection, now you can find out when your bus is coming -- at any of Metro's 12,000 bus stops," said Metro Board Member Christopher Zimmerman of Arlington.With the phone service, you can call (202) 637-7000 and enter the ID number of your stop, as shown by the sign located at each stop. In the online version, you choose a bus line in the WMATA system, which stop you're interested in, and which way you're going, and the service will tell you roughly when the next bus or couple of buses will be at that stop. Assume there could be a bit of variation between the NextBus time and the actual arrival time as you never know what could happen (red/green lights, construction, etc) that might slow the bus down a couple of minutes or cause it to get there a couple of minutes early.
Click here to see an example (10A bus at Mt. Vernon and Reed Ave headed northbound). You can also bookmark your stops and view the whole bus line on a map. In map view, you can click on any stop on a line and it will tell you when the next bus will be there and will actually show you where the buses are and which way they're going right now.
If you're not sure which bus you need to get where you're going, you can enter your departure and destination into WMATA's trip planner or look at the bus maps online.
NextBus should make it much easier and less frustrating to take the bus since you will know when to expect it and you waste less time standing by the curb.