Digital cameras and mobile phones
Many cameras/phones allow you to record short video and/or audio clips, which you can then upload to YouTube, Google videos, Blip.tv and/or link to this site... If you use Google Video, you will be able to embed your video in your slam page, otherwise you can link to it.

Voicethreads
A voicethread is "a tool for creating conversations around media". Here is an interesting example .

Animoto
.... is a tool for annotating videos and more, see the 60 second video on the front page of animoto..

Photo sets or albums
You could use the Photo Gallery/Album feature on this wiki, or the Set/Slide show option on flickr.com, see an example of this in Sample Slams

Slideshows
You can use powerpoint (or keynote) and share your presentation on Slideshare. You can even add audio to it by creating a slidecast (see how here) Example here.