Slideshare is an online presentation sharing website. You upload your presentations to slideshare and this enables others to download it. They can’t edit your presentation (well they can, but they have to download it, change it and then upload it as their own). It’s useful for conferences  – you can upload your presentation beforehand and then run it from slideshare.

There are many library 2.0/2.1 presentations on slide share including several by Helene Blowers.