PP is useful enough for lectures and presentations, but I hate getting them on the mail. Some people seem to think all information should be distributed as a .ppt and send files as attachments in mail; then you stare and wait for this miracle to open, it has three sentences of text - you could have written that to the mail you clod!!! Ever hear of copy-paste?
I use PowerPoint often because my audience is usually of two different languages. When I speak in one language I like to have the translation up on the screen behind me. I think that's makes for useful presentations. Someday I should wake up the members in my audience and ask them.