I built this over the Thanksgiving weekend to keep a track of all the classes: http://www.class-central.com/

That's really nice, I think it deserves its own submission.

A nit: the start date field, in an amusingly non-intuitive way it took me a few seconds to figure out, sorts alphabetically by the month's name rather than by the date.

Nice list, thanks for putting that together!

Nice! Will definitely come in handy :).

Don't forget to add Model Thinking to the list!