Jim Gustafson just gave me a very early demo of a new presentation tool for Second Life educators, and businesses that need to present to groups. Right now it's very beta, but the potential is there for sure. The package consists of a screen and a deck, the screen shows the visuals, and what you want to say is put into the general chat.
I can see this being great for SL teachers that have to give regular classes, but also, as Jim has planned, given a bit of tweaking, for business as well. As soon as it's complete we'll let you know, but if you want to check it out as it stands now, you can grab a copy for free inworld at EduIsland 2 [TP].