One of the most basic must haves of any event where presentations are made before a group of people is the availability of the appropriate audio visual equipment. Be it inside a conference room where there are 10-12 participants, a small seminar venue where there are 20-40 people eager to learn from you, or an auditorium where a crowd of 300 or so have gathered to listen to your whitepaper on the evolution of the widget. Having the right audio video equipment takes away the need to strain your voice just to be heard (try doing that in an auditorium!), or pass out multiple copies of what you want to present, and encourages focus and interaction, thereby significantly enhancing the experience.
If you hold presentations on a regular basis for small groups in a small venue, then it might make sense for you to invest in basic audio visual equipment (i.e., a multimedia projector, laptop computer, and a simple sound system), which should not cost you too much. However, if your presentation events are, for example, just a couple or so times per year, in venues that are in excess of a sitting capacity of 100, then the option for investment on the appropriate audio visual...