Glad I'm not the only one. :-)
However, that is rather a specific case, albeit a common one. I have lost count of how many times I've seen even very experienced sysadmins do something disastrous by accident that is entirely due to the poor usability of some Linux shell or other command line-driven software with a similar design style and culture.
I have seen someone nuke an entire system, with a shell script that failed at string interpolation and literally did an 'rm -rf /', after I explicitly warned them of the danger and they thought they'd guarded against it. That person was a very capable sysadmin with many years of experience, but expecting anyone to never make a mistake with that kind of system is like expecting a similarly experienced programmer to write bug-free code with nothing but an 80x25 terminal window and a line editor.
That being said, there's certainly something to that one event doing more to reform my being fast and loose with destructive commands than years of being told/telling myself to do so. (Something likely being that I'm apparently a slow learner.)
Now that I think about it, it shouldn't be to hard to turn this into a workable product for general use. Automatically take a snapshot every 5 minutes, and present a the user a program that broweses the filesystem at time X, probably with integration into the filemanager to restore files/folders. Practically speacking, it needs some form of pruning. Probably along the lines of save every 5 minutes for the past hour, etc. My only concern with this is how optimized for frequent snapshots Btrfs is. Either way, I know what I am doing this weekend.
Something like this? http://java.dzone.com/news/killer-feature-opensolaris-200
Of course, I might be reading to much into the continous nature of a slider. Does anyone have experience with that feature?
In OpenSolaris it just used cronjobs to create zfs snapshots.