Need to whip up a snazzy presentation fast? Log on to Sliderocket with your Google account and dive into its slick templates. You can embed images, flash objects, videos, and audio, and export your presentation as a PowerPoint slideshow or a PDF. The free, casual-use version works online only, but the paid version for businesses supports online and offline slideshows (plus some other goodies).
Note: This link takes you to the vendor's site, where you must sign up to use this Web-based software.