Progress indicator (was: scrollbar alternative)

[Leo]

On 2010-03-16 12:44 +0000, Lennart Borgman wrote:
> I like the feature. I think something like this should be in Emacs.
>
> Attached is a little bit more elaborated version. Name suggestions are
> welcome.

I was making a proposal to emms maintainer lukhas about porting that
code to emms-playing-time (you could imagine how nice it is to show the
playing time this way), but then realised emacs can benefit from having
a general facility of creating nice visual progress indicator like this.
What do you think of this idea?

Leo