I may have posted this before, but it bears repeating...one of the major challenges for speakers (and their audiences) is being able to see what's being presented, particularly in large venues. And while it's easy to change the font size in your IDE so that your code's easy to read, changing other elements tends to be more involved...unless...you use a Windows XP theme to handle a bunch of settings all at once.
So to help you out, here's a link to a theme I found a while back that sets a high-visibility scheme at 1024x768. I'm not sure who the original creator is, but it's been very helpful to me over the past couple of years. Note that this doesn't modify the font size in the Visual Studio code editor, so you'll still need to do that, but I think you'll find that audiences really appreciate the readability of this theme when you present:
The other nice thing about using themes is that it's very easy to restore your previous settings (make sure you save any custom settings before you apply a new theme).
One other thing that is always worth repeating a link to is Scott Hanselman's terrific post on presentation tips...read it and live it. There's also a powerpoint version available on Scott's site.