Life logging. Yes, I know. Some people tend to overdo it, but hey, there's an interesting concept here - easily capturing what you did, when, where and what you feel about it, if it was a good experience or a bad one, musings, etc.
Most people using facebook kind of do it already. But there should be an offering of services and standards that help people log what they do without giving all their data to one company.
For example. Path is far more focused on keeping your data private and sharing with a small group. Specialized photo communities like Photonado help us make our "diary entries" in the form of snapshots we take of daily life. Last.fm and the like help us remember what we've listened to. And Nike's FuelBand tracks our physical activity.
The evolving openlog (at github) and ActivityStreams standards will help us store, syndicate, re-publish, share, keep-private, push or pull all this data. Let's hope that great products like Nike's FuelBand open up, offer easy APIs and let us collect the data we collect with them on whatever platform or service we want.