When you need to show a proposal to a customer or client or make a presentation at the office but don't have audio/visual equipment, you can usually rent what you need very easily. Many A/V companies have a wide variety of items that will work for just about any presentation. Before you do rent, however, you want to ensure you know all the pieces available to you so you get the right ones for your needs. Note a few tips in this regard.
Data projector versus overhead projector
A data projector uses a USB port to read your slideshow or other presentation and allows you to run it right from the projector itself. You would need to ask the rental agency about the type of program that the projector is compatible with; many work with MP4 programs, which are basic movie files. Others might work with PowerPoint or a similar, common program.
An overhead projector is often used in schools; this has a flat screen on which you put a transparency, and the projector will then project the transparency onto a movie screen. The advantage of an overhead projector is that you don't need a program for your presentation; you simply prepare the transparencies as you would any other document. You can also write on the transparency, and this writing will show up in your presentation, giving you more flexibility with your project.
For even more control over your presentation, you might opt for an interactive board. This board reads the information on the screen and allows you to move it around with the touch of a finger, write on it with a special pen, or otherwise actually interact with the information. This can be very good for schools or other situations where you want to encourage audience participation. This can also allow you to incorporate information you get at the presentation and cannot prepare beforehand, such as answers from the audience or their questions.
A document camera works like an overhead projector, except that you don't need transparencies for this equipment. A document camera has a long arm that extends a camera over a document; it looks something like a gooseneck desk lamp. The camera then photographs the document and projects the image onto a screen. This allows you maximum flexibility with your presentation; you can include papers you've prepared beforehand and also papers that are given to you during the presentation, without the need to run them off on transparency paper, as you would with an overhead projector.
Work with a company like Fordtronic Video & Sound Pty Ltd to learn more about A/V equipment that will enhance your presentation.