I've used Prezi once and it took me so long to do I gave up on it. I first came across it last year at a Kingston University Partners' Day when a speech was given by Ian Collins from University of West England. It looked like an interesting way of presenting, and, being quite bored of PowerPoint, I thought I'd give it a try. As it happened, I had an interview coming up at a rather good University and the content of the presentation I had to deliver seemed to fit the profile of what a Prezi should be i.e. lots of connected ideas and topics. However I spent about three evenings thinking about the content and then had to spend another three evenings just trying to put it together. I could not get a handle on wizziness and seasick inducing motion. I came to the conclusion that when style starts taking longer than substance it's time to call it a day. In the end I transferred all my content to a PowerPoint but still kept the theme of connectedness.
However, saying all that, I have now seen a few Prezis and they are getting better. I think my problem was that I as treating it like a PowerPoint i.e with a linear structure. Also, I've since found that having all the content structure of the presentation laid out before hand greatly helps. I will give it another go but it won't be for work any time soon as we have standard PowerPoint templates for our referencing sessions and the information literacy and Moodle sessions I deliver are all practical.
Slideshare - I don't use this for work as we keep all our documents in one work area. I do use it a part of the CoFHE LASEC Committee; we keep our presentations from our events on it, which means we can easily give people a link to this rather than emailing several different PowerPoints to numerous people. It is also compatible with LinkedIn so I have added them to my profile. I find looking at other people's Slideshare accounts very useful when I am researching a topic as they are very quick to trawl through. The most recent ones I found to be of value were the JISC slides when looking for information on digital literacy. There's a wealth of information here.
Overall, this Thing has encouraged me to give Prezi another go and reminded me to look at other's slides more often, as well as update my LinkedIn page. So all in all - a worthwhile task.
And the job - sadly I was beaten by an exceptionally strong candidate - I wonder if they used Prezi...