[Groxx]

The "step back in time" feature is sort of gimmicky, but does mean you can rewind even Curses terminal applications. Rarely actually useful, but it has saved me a huge amount of hassle a few times.

[mmahemoff]

Vim also has history via the undo-branches feature. e.g. ":earlier 15m" to go back 15 minutes.

[Nick_C]

And the Gundo plugin extends that even more with a history graph and preview pane that shows diffs. A must-have plugin for me.