I want to see what my options for groups are. Ideally a list sorted by number of members, like http://redditlist.com/. Or is my only option for discovery looking at what groups my friends have?
How can I see a list of all Fitocracy groups?
fitocracy
Click Connect in the top nav bar and you will get a list of all groups. They're alread sorted by number of participants and you can filter them by what you're interested in.