A kind of Time Machine
The Time Machine in Mac OS 10.5 saved my butt a few times in the last few months. Getting back an older version of a presentation when you´ve saved a short version of you presentation in the same file as the long version a few days earlier is quite handy. Solaris is now capable to do a similar thing (albeit the implementation is vastly different): Time Slider is based on periodic ZFS snapshots and presents them in a nice way:
Time slider is one of the new feature that will be available in OpenSolaris 2008.11.Time slider provides an automatic way to backup your data on the same disc using one of Sun's ZFS filesystem unique features, snapshots. With time slider you can browse and recover files from snapshot backups using the GNOME file manager.
When you click on the life buoy in the File Brower you get a slider to step back in time based on this snapshhhhhh … wait … just look at the screenshots at Erwann Chénedé’s weblog. A picture substitutes 1000 words and this feature is outright incredible. Excellent work!