Acknowledgments

To any of you who might be writing a paper or preparing a presentation - anybody who is listed as a co-author on whatever you are preparing should not be mentioned in the acknowledgments section/slide.  Your co-authors are supposed to help you - they're just as responsible for the paper/presentation as you are.  (Which is why nothing should be published/presented with your name that you haven't had the opportunity to fully review/critique, even if you only contributed to a small portion of the final product.)

Example:

If you're giving a student seminar within your department, generally you are the only "author" listed, so it's perfectly fine to thank your advisor.  However if you're writing a paper or preparing a presentation for a conference, your advisor would be listed as a co-author (in the physical sciences at least), and therefore should not be listed in the acknowledgments.

I feel like I've been seeing this a lot when I watch practice talks lately, and a friend's (jerk of an) advisor sent a comment to him about a paper draft that said "anybody else??" when he "only" listed two (non-authoring) labmates who had been useful in discussing data and proof-reading.  The advisor should certainly know better (and stop being an asshat), and before now I'd thought this was common sense as far as the younger students are concerned...