Perhaps this is only because of my own, but it's a real experience:

1) Was visiting: http://moodlemoot.moodle.de/course/view.php?id=5 as guest
2) Saw the "Enrol me in this course" link (in the Administration block)
3) Pressed it and arrived to one page showing me the course info.
4) I didn't saw the "Login" button near the footer nor the "Login to Anmeldung" breadcrumb,
5) I thought "Uhm, what's the objective of this page ?"
6) II wrote this improvement request.

IMO, near the top of the page (over the course info), we need some box explaining the situation, something like:

"Now you are guest and you want to enrol to this course. To do so, please, press the "Login" button. After login with your credentials, the enrolment process will begin".

And then, the "Login & enrol" button.

Something like that will make the process easier for blind people like me.

Ciao