A useful but probably unintended side effect of the new Timeline profile, is that it allows you to very easily see who unfriended you on Facebook over the past few years.
UPDATE: Facebook addressed this issue and removed all ‘lost’ friends from the yearly new friends lists. Consider the instructions below obsolete.
1) Select a year in the sidebar (TIP: Start with the year you joined Facebook and work your way to 2011)
2) Look for the Friends box that shows how many new friends you made
3) Click on the number of new friends
4) Those with an “Add Friend” button next to them are the people who unfriended you (or where unfriended by you)
5) Feel bad all day wondering why X unfriended you back in 2007.
