As explained here, it would be nice is we could have one interface to viewing the history of what you did on your computer. Below is a mockup:
It would be relatively easy to implement a simple prototype of something like this on GNOME at least for documents. You could just watch the recent files list for changes and record the times in a db and create a display based on that. A fancier approach would be to patch gnome-vfs, but that's more invasive.
Of course, the applications and people part would require a bit more work.
You'd have to be careful not to re-implement that most /hated/ part of MSOutlook - the Journal!!! -- JonathanMatthewsLevine
It doesn't look any different to Outlook journal at all, except the concept has history of applications used. -- JeromeGotangco
Maybe something for beagle? -- HermanBos
Looks a bit like Onlife for OS X. -- Slamb