Using computers at trial takes technological know-how and plenty of practice before you've actually set up your equipment in court. A basic set-up includes the following elements:
Hardware: In addition to your computer, you'll need an LCD projector and a screen, if not provided by the court. To ensure you can use the computer for many different trials, store your documents on an external hard drive that connects to the laptop through its USB port. The manipulation and presentation of paper documents can be accomplished with an Elmo. If you have the means, consider replacing the projector and screen with monitors for the jury, judge, and opposing counsel..
Software: While you might be able to get by with presentation software like Powerpoint, you should also consider software that allows to you present and mark-up your exhibits on the fly. Two examples are Trial Director and Sanction, which are compared in an article at Law Techology News. Used in conjunction with a bar code reader, you'll easily get the documents you need up on the screen.
Be sure to scope out the courtroom well in advance of trial. After you've decided where you'll place the projector and screen, find out whether the location of the electrical outlets will require additional cords or cables.