I myself have been trying to do this for the last decade or so. Some devices you might like to look into.
Pretty light head mounted camera. Can record about 8hrs of footage at lowest Res. I had to hardware hack it and attach a bigger battery as it runs out before it runs out of recording. Every night I slurped off the recording to my Mirrored raid "lifelog" drive at home. Look into some good VJ software. Almost any good VJ software has the ability to tag and index parts of a video. If something noteworthy happened in the day I'd take 10 min in the evening to jump to it and tag it in the SW. (hence for future search of little Timmy being cute)
Basically if you want to go 24/7 (actually just when you're awake) you'll need to build your own rig. I recommend a pinhole camera from a spy shop online. They make cameras that look like buttons you can integrate into your shirt. A Raberry Pi and a huuuge SD card will get you a days recording. In the evening pop the SD into the PC and have an auto-sync pull the data to your big redundant life array.
The only thing that's kept me from keeping this up is storage. Even LQ video and mono audio and you're looking at gigs a week. It adds up really fast to about a HD a week. Not sustainable. As soon as Drives get bigger I would be doing this for sure.
Why? So if I die the future super beings can pretty faithfully recreate me from the records. My future simulated me will be way better resolution than the rest of you jokers.