For the non-MSFT programmers here, Scott Hanselman is well known in the MSFT community as one of the top authors and speakers for ASP.NET and .NET in general. The man is awesome.

I've always liked Mark Jason Dominus' Conference Presentation Judo talk: http://perl.plover.com/yak/presentation/

that was pretty weak, actually.

One that I've used successfully is to consciously transform my "um"s and "ah"s into moments of silence.

Instead of looking fumble-y, I look thoughtful.