Create a list of characteristics such as "likes chocolate," "has two children," or "can swim." There should be 10-15 items, and you can relate them to your lesson if you wish. Then let the learners mingle and get signatures of other learners who fit the descriptions. Make sure they are using appropriate question forms ("likes X" becomes "Do you like X?") and aren't just pointing to the items on the page. This can be made into a Bingo activity by putting the items on a grid.