Version:           unknown (using KDE KDE 3.2.1)
Installed from:    SuSE RPMs
Compiler:          gcc 3.3.1 
OS:                Linux

In OS/2 (which I haven't used in 4 years) there was a nice feature which allow a user to specify a corner of the screen.  When the cursor was moved to that corner (say the upper left), the screensaver would start immediately.

With all of the nice screen savers in KDE, including the slide show, this would be a nice feature to have.  In addition, if the 'lock' feature was being used with the screen saver, it would allow a user to lock the screen and get up to leave while leaving the screensaver running.  I do not recall whether there was a delay involved (as in 1 sec or less) before the SS started, avoiding an accidental locking if the cursor were momentarily moved to the corner, but any such delay could be fixed in my opinion to make things simple.