I watched quite a number of slide shows on www.slideshare today (I wonder how many more tomorrow, day after tomorrow ...?). My first impression was: GREAT! Of course it is something to use during all sorts of presentations, library inductions etc. The second thought was much less enthusiastic. Many of the slide shows were just a number of pictures/sentences which may mean nothing to a viewer unless used as an ilustration af a live presentation. However some were fully "self sufficient". I liked, among others, Phil Bradley's "Twitter 101 for Librarians" and "The Plagiarism Code" by Andy Priestner. I suppose every slide show prepared for a particular presentation would also be published/posted somewhere else together with the whole text of the presentation, most likely on the official website of an institution, a conference or an author. It seems they are not really in the right place among humorous, entertaining or geographic slide "showers".
Seeing all sorts of slide shows may also be an inspiration to produce something that would be more appropriate for a particular library or reflecting one's interest etc. But unless it has any universal values it should stay where it "was born". Not necessarily the whole world has to know about and share it.
Never mind all the doubts. Once again - thank you 23 Things Cambridge Team for bringing the Things to those of us who had never heard, or heard but not seen or used all these, before (I am not refering at anybody but myself, of course). Are they not just great revelations?