ARI Image SlideShow extension creates slideshow based on images from specific folder(s) or from Flick.
Main features:

• User friendly interface;
• Can resize images and cache them;
• Can display images in random order;
• Support ability to sort images by name, date;
• No flash. Pure javascript and CSS;
• 54 transition effects;
• Can display Flickr photos based on Flickr photoset ID(s) or user ID(s);
• Can show images from Picasa albums;
• Provide ability to create your own themes;
• Can start slideshow automatically;
• Highly customizable;
• Supports possibility to show images titles which you can define in CSV file;
• Can display module in Joomla! articles with help ARI Image Slide Show plugin;
• Works in all modern browsers: IE6+, Opera, FireFox, Google Chrome, Safari and other;
• It is open source and under GNU/GPL license.

Note: The extension works fine if images have the same size, otherwise images may look ugly.