For those of us in love with Slideshare, via Techcrunch I see that there's a new feature--audio synchronization. This will be great for making your presentations "full service" for embedding into wikis, blogs, emails, etc. Here's a demo.
Also--while on the Slideshare site I noticed that PowerPoint Karaoke is getting hot. Apparently in this version, you present to someone else's slides as they are shown--randomly. Slideshare has helped things along by creating a Slideshare Randomizer that will automatically pull Creative Commons-licensed slides with tags you specify and run them for you. More here on how to run your own karaoke event. Could be a fun way to end a training session or to run a fundraiser--have people get sponsors and then participate in a karaoke show-down.