Open source eDiscovery project, FreeEed, got a concept of history. History is shown in a separate window that can be open or closed it will. You can all erase it and start with a clean slate.
History is real-time, and it frees up the user interface to do other things while the software is crunching the information.
The code is currently in "Branch 2" and will be part of the 2.5 release.