Re: highlight with mouse then shouldn't need kill-ring-save?

[Richard Stallman]

    If we highlight a region with the mouse in emacs, it is available on
    the X windows paste buffer.

    But if we just set a mark and then say, go to the end of line, we see
    the region highlighted just the same, in blue, but it is not available
    on the X windows or emacs paste buffer.

Are you using transient mark mode?

Perhaps it would be good in transient mark mode
to set things up so that when the mark is active,
the region is available as a selection.