There is just something about a magic trick during a public speaking engagement that grabs people. The nice thing about it is that as a public speaker who uses magic to make a point, you are not held to the high standards you would be held to if you were a professional magician.
I do some simple magic that would probably make a real magician throw up, yet I get comments from the audience that they loved my "illusions." Think about some of the points you make during your speech that might need a little extra flair to make them memorable.
Visit a magic shop and tell the proprietor what you want to accomplish and that your skill level is zero. Most good magic shops have literally thousands of tricks to pick from for all skill levels and all audience sizes. Also, you can surf the web via entering search words such as "magic", "wizardry", (etc) to view various magic related web sites to glean ideas from them.
Magic tricks are also a fun way to add some lightheartedness and WOW factor to your presentations. The points you make and the comedy aspect of the magic usually come from the "patter" (what the magician says while doing the trick). You can even buy books of comic patter. Many magic tricks are now on video which makes them infinitely easier to learn than trying to read them from a book. An excellent tape for rope tricks is "Daryl's Rope Tricks # 7." Your local magic shop probably has it and if they don't they can probably order it.
I really like to learn magic from videos because you can see the trick in action. Reading them from a book is OK, and very useful, but you just can't beat video training. Two good magic videos for speakers by master magician Tom Ogden are "Teaching and Training with Magic" and "The Magic of Creativity." I got these two videos from Royal Publishing & Walters Speakers Services (626) 335-8069
