Okay, I will try to run down the list of submissions so far.....
sammy....Very clever fitting the domain into a chalkboard like that. My original thought was to have something rather stiff, yet your logo comes across as fun while still getting the idea across. A solid entry that I will have to think about. Not sure of any changes you need to make.
blue- I like the second entry, how you fit the tv into the "O", but I do not like the font that much. If you are just glancing at it, it almost looks likt a mixture of capitalzed and small letters. Would it be too much trouble to see it in another font?
dancam- I like your entry very much, it is simple, but gets the idea across quickly.
zombie- Nice approach, it has the academic feel that I want, though I am not sure about the acorn. somehow the image should represent the act of teaching. But for $40, I know you don't want to spend a lot of time on this, so do as you wish! Also, Instructor is misspelled.
zenius- Interesting concept, I would like to see Instructor.tv in a stronger font. But I do like the idea.