We also have a muddy point helper. The concept is simple, sometimes students have "muddy points" - things they need help with. They write a notecard about their problem, drop it on the helper and it is automatically forwarded to you. Yes, there are other ways to do this, but it's free and makes things easy for folks not used to the SL interface.
Then we have a quiz tool. Set up your quiz with MCQ (up to 5 answers) or *short* open questions (up to 1024 characters in one utterance). Answers are recorded and emailed to an address you define in the notecard which asks the questions.
Then we have an "automatic presentation player" - there's got to be a better description than that, but it does the job. Again driven from a notecard, this player will read out the lines you put in it at a controllable rate. It will also change textures on the display on command, and play sounds as required.
Finally we have a meeting/class controller. There is a simple in-world server and a number of light/buttons (the lights are copiable). Once the meeting is running the users touch their button to register and then, if they wish to contribute, they touch it again to join the list of speakers. The server allows the teacher/moderator to control the list, hush people who speak across others, throw the discussion open to the floor etc. The buttons change colours slightly to indicate position in the list - the moderator also gets a hovertext "top three" speakers list.
These are available on SLB, SLEx, in world in Eloise's MiniMall, Literature Alive in Iukekini Island, the ICT Library and the Tea Geeks area.