OpenOffice Impress and the Sun Presenter Console
Altough my last presentation at the university went not very well I'd like to mention one fine piece of software which makes presentations a lot easier for the one standing in the front of the crowd (and without I would not have had a bad but catastrophic presentation).
The Sun Presenter Console is a plugin for Impress which adds functionality to the presentation application similar to the PowerPoint Presenter view. In fact this means, that if you have turned on multi-monitor support and are running a presentation with a projector it enables you to run the presentation as you know it on the presenter and have a completely different view on the presentation on your computers screen. This "Presenter Console" has a smaller view on the current slide, a lookahead of the upcoming slide, (depending on the configuration) a view of the notes-area for each slide, a small timer which shows the running-time of the presentation and last/next-controls.
Altough the info on the download mentions this plugin to be compatible with OpenOffice 3.0 it works flawlessly on my OpenOffice 3.1. Just make sure, that you have the presenter connected to your computer or laptop and set up the correct presentation screen in the settings for the screen presentation.