Slide Six is a slide show hosting service that offers you the ability to add your voice narrations without having to create, upload, and sync a separate audio file. Slide Six does this by allowing you to record your narration directly through the Slide Six site. To use the feature just upload your slide show and then record your voice as you go through your slide deck. Slide Six also allows you to upload attachments to complement your presentations. YouTube and Vimeo videos are supported within Slide Six.