EDIT: I created this when I worked at SlideShare years ago. Apparently SlideShare doesn't support Keynote files anymore and so these steps DO NOT work. Your best best to upload a Keynote file is to save it as PDF or as a PowerPoint file and upload that. You can now upload Apple Keynote files to SlideShare. Here's a quick how-to.

1. Upload Apple Keynote
to
SlideShare

2. Select your Keynote file and Compress it to a ZIP

3. Select your Keynote file and Compress it to a ZIP

4. Upload this ZIP file to SlideShare

5. Hit Publish and you’re done!

6. Made by SlideShare on Keynote