This is a summary of advice given on Mac Ministry List about making a slide show which can be exported to Windows if required.
For a quick and simple slide show, use iPhoto. iPhoto will play the show to a song or playlist if you like. The latest version will automatically adjust the length of showing each picture to fit the length of the playlist. (So the more music you use, the longer each picture will be on screen.)
iPhoto can add various effects such as the "Ken Burns" effect which includes panning and zooming. There are also different "themes" or templates that iPhoto can use to create a more interesting slide show, putting more than one pic on screen at a time. Play with the choices to find what would be best.
iPhoto can then export your slide show to a variety of sizes for use on mobile devices, computers, etc. Export it as a QuickTime file; even Windows does QuickTime. You can then play it back on any laptop, and set it to loop if desired to play for long periods of time.
You can even burn the Quicktime file to DVD with iDVD or Toast.
If you want to use different timings, or match them to a sound track, or multiple images per screen, you will want Keynote.
Keynote integrates directly with iPhoto. You can drop an iPhoto folder into the slide navigator of Keynote and it will automatically put all the photos into a slideshow.
Use simple dissolves, and no MagicMove, if you are going to export it to PowerPoint.
Animoto is fast but still looks professional. 30-second presentations are free but there is a charge for a longer or higher resolution download.
Compiled by Neville Reid from advice on Mac-Min in September 2011 from Jon Glass, Chris Howard, Barry Wiseman, Kimberley Edmond and Timothy Archer.