What you do online is data
Zachary Seward for the Wall Street Journal gives some thought to what he does online via applications like Twitter and Foursquare. He notes, "[I just] ended up with this wealth of data."
Lifelogging is often attached to obsessive tickmarking in notebooks and counting things that don't need to be quantified. It keeps getting easier to collect data about yourself though, and in due time, lifelogging will feel so natural, you won't even have to think about it until you're reviewing your very own [insert name here]-tron report.