Software For Slackers: Lockout
Matijs van Zuijlen writes "Having trouble getting work done? Reading Slashdot too much? Lockout will enforce some dicipline. It will lock you out of your internet connection, and then lock you out of your root account so you can't unlock it. For a limited time of course. Use at your own peril."
... and whatever the equivelent is in other bootloaders.
I.e. with physical acess to the box (which, in the case of this software, you will), you can always recover a lost root password, by booting single user, and then changing it.
In the event that you've locked up your bootloader with a password, this util doesn't change that.
If you've really locked it up the wazoo with crypto all over the place, I think it's recoverable with a boot disc (as you'll have the bios password, or be able to wipe it, to re-enable booting from CD). Mind you, if you've done that then you're not likely to be the sort of person who needs this util.
Frankly, I'd agree with you about self-discipline - there are very few cases where an externally imposed discipline is useful as anything other than a tempory measure. This is not one of those cases, in my opinion.
It is, however, always worth knowing how to recover from any problem, where it is possible. Backups not needed in this case.