Photo by Nivad

Last week we got a little too excited about the impending expansion of cell phone service in the Metro system, but now it’s official: T-Mobile, AT&T, and Sprint Nextel customers should be able to use their cell phones inside Metro’s 20 busiest stations starting first thing Friday morning (the Post says it’ll be turned on at midnight, but of course the system will be closed by then). Verizon customers could already access their network inside the same stations, and they will continue to have that service after the change.

As a reminder, the stations included in this first phase are: Ballston, Bethesda, Columbia Heights, Crystal City, Dupont Circle, Farragut North, Farragut West, Federal Center SW, Foggy Bottom-GWU, Friendship Heights, Gallery Pl-Chinatown, Judiciary Square, L’Enfant Plaza, McPherson Square, Metro Center, Pentagon, Pentagon City, Rosslyn, Smithsonian and Union Station. The rest of Metro’s stations, and eventually, tunnels, will get the expanded service over the course of the next two years.

WMATA is holding a big launch event for the media at 9:30 a.m. tomorrow morning at the Judiciary Square station, with General Manager John Catoe, Board Chairman Jim Graham, WMATA’s tech team and reps from all four cell companies expected to be on hand.

In the meantime, be sure to let us know how the service works for you on your morning commute tomorrow. Send us emails at tip@dcist.com or tweet us at @DCist_Updates.