Note - this is written just to help. I know I'm not a perfect presenter - but I just wanted to share a few tips for other potential speakers out there...

• Bump up your editor's font size. Bump it till it looks big. Then double it. Learn how to maximize the code portion of your IDE since your code will most likely be off screen. Write your sample code such that it is multi-line - this will cut down on the amount of side scrolling you need to do. (If your editor supports code wrapping then this is a non-issue.)
• Bump up your browser's font size. Don't worry how ugly it looks. I can't tell you how many times I've been in a presentation and while I could read the slides, and maybe the code, the browser was kept at the normal font size. Yes - it may look a bit ugly. Get over it.
• Name your files right. This isn't for the audience per se - but for the speaker. If you are talking about foo, you want to make your example file named foo_example.cfm, or something similar. It is pretty embarrassing when you go to show an example and have trouble finding the relevant file. I'm kinda good at this, but I still tend to forget what the right file is. The best thing you can do is use the Notes feature of your slide program and list the right files for each slide, then print out the notes before the presentation.