InTheRooms has both a Wiki that contains information for thousands of 12 step meetings as well as regularly scheduled online meetings at their website.
As of August 2012, they have cataloged thousands of meetings for Alcoholics Anonymous, Gamblers Anonymous, Narcotics Anonymous, and Overeaters Anonymous. You can easily put in your address or zip code and the site will list all of the nearby meetings on a Google map. You can filter by day and time and meeting type.
They also have regularly scheduled daily online meetings on their website that use video and voice. For the online meetings, you can choose to participate or just observe. They also have a text chat room that is always open and usually someone is there to chat with.
To see the meeting listings or participate in the online video meetings, you must register and join the site. It is free to join.