This is a simple way for a group that is meeting again after not meeting for several weeks or months to catch up on each other's activities. Like the Power Line and the Learning Interview, this activity involves making a simple shared chart that "bubbles up" individual experiences and, at the same time, enables you to see collective patterns of activity. (I got the basic idea of using a timeline as a basis for sharing individual experiences and finding patterns from the Project South timeline activities.)
Draw a simple time line on the board, or on big paper posted where all have access to it and can see it. Divide it vertically into months (or weeks, years, etc). You can also divide it horizontally into different types of activity. For example, in English for Activists, I divided the timeline vertically into two months then horizontally into two basic categories: "work/activism" and "personal life/other" because I wanted to check in not just on work and activism but also on people's personal lives. ("Whole activist" learning.)
As people come in at the beginning of a meeting/class, ask each person to add one or two experiences to the timeline, writing just a few key words. For example, one person wrote, "set up concert in jazz bar." Another wrote, "Friday demos." When everyone has put their experience on the chart, the joker chooses one item and asks the person who wrote that to explain it. The person explains and then chooses another item on the board and asks that person to explain, etc.
In activities that involve personal sharing, it is important that everyone have an equal opportunity to speak. If you have a big group and having every person speak about every item is too time consuming, you can limit it at the outset to ten items, then check in and see if people want to continue. Or you can limit the activity to 30 minutes (or some other period) and then check in. Or, you can have people form small groups and have each person in the group explain their own items to their group members, then check in with the whole group asking people to share one or two particularly surprising or interesting items.
You could use this activity as a starting point for a discussion about the group's activism -- looking for patterns of shared activity, or differences. People can make sentences describing the group, "we all...." or "Some of us... while others..."
You can also use this activity to fish for themes that people want to discuss further in future meetings/classes, or experiences people want to share or investigate.
You can ask people to choose one of their items and do a Ten Levels of Why game -- "I went to the Friday Demos", why?
You could use this with a new group, as a way to learn about individuals -- what they do and care about -- and about the group.
You could play with the time scale, making a timeline of decades or of hours... and with the categories... Lots of room for tinkering here.