Has anyone developed a feature allowing a whole course to be hidden? It would be very useful if courses that are not currently taught could remain in Moodle so that the teacher could work on improving them for the next use, but students should not be able to see the course listed anywhere.
This isn't in the bugs database yet, but is coming very soon. Someone is sponsoring that feature.
That is wonderful. Long live moodle.com. 
Amen. (And I hope that Martin becomes a Moodle-millionaire.)
I appreciate the thought, but I'm just hoping I can make a simple living first! 
Many years later: I still hope you become a Moodle-Millionaire.
You have earned it.
Art
Nope, not yet. I'm still drawing a normal salary and paying off large mortgages in my home town of Perth (one of the most expensive cities in the world).
However, because of support from the community and Moodle Partners, my company is able to directly fund around 20 people to work on Moodle full-time and that is a beautiful thing that I am proud of.
Hi Martin!
Keep up the good work. I'm rooting for ya'. I'll barrack for you.
Martin, Sir Barton Pope, from Adelaide and creator of Simpson-Pope whitegoods etc, was once asked what his greatest achievement was. He thought for a moment and said "Giving employment for 3,000 people." OK, 20 may not be 3,000, but you must admit, Moodle is reaching millions and is providing a far greater springboard for them than just simple employment. I would suggest that this is a pretty great achievement and this is what you and your 20 employees (and brigade of devotees) are doing, not many people can say that...