In all seriousness though, I've been to more than my share of lectures for med students, residents, and beyond. I've heard some people who were clearly naturally good speakers but didn't know how to give a good lecture. Anyway, in my opinion, these are tips you can do to give a good powerpoint lecture:
Lots of pictures! Pictures to illustrate your points, not stupid clipart.
Limit the number of words on a slide. One thing that drives me nuts is a slide filled with so much text, you can't even begin to read it. What's the point?
Involve the audience if possible. A good speaker is engaging without having to even talk to the audience, but if you're like me and not the greatest speaker of all time, asking questions of the audience keeps them awake.
Involve the audience BUT don't pick on the audience. I still will never forgive this pathologist who called on me by name to answer a question during a grand rounds with like 200 people in the audience. Even in a small group, I think it's kind of mean.
Don't have text fly in from off the screen. Do people still do this? If so, stop it.
Don't go into too much detail about research studies. Especially YOUR research studies. Unless of course, it's a journal club.
Repeat key points. I've read that people can retain 3 points from any lecture, so figure out what those 3 points should be and make sure to hammer them home.
Don't go on too long. After a certain point, no matter how good your lecture is, everyone just wants to leave and won't hear a word you're saying.
Also, if you can possibly manage, do NOT show photos of your children and/or dog during the lecture. Seriously, I hate that. (I'm sorry, I didn't mean that. Your kids are adorable. I love that little hat your daughter is wearing.)