I like to give my presentations freestyle, with no written script, and I very much enjoy doing that. It means preparing the presentation so I get all my prompts from the Powerpoint, and doing multiple test runs (but then I guess everybody has to do these). For those test runs, I really like to use the "rehearse timings" function ("Neue Einblendezeiten testen", for the Germans among you). This gives me a running count of how long I've already babbled to myself, and in the overview pane in the program, I can see how long each slide took me to narrate everything I wanted to say. This makes it easy to see if a slide has too much babbling done, and I should probably split it, or lets me see at one quick glance where I might be able to cut something. (Just be aware, if you are planning to try this out, that PP will automatically adjust the settings for the presentation to automatically advance the slides according to the rehearsed timing; make sure you set your presentation to advance manually before you save the final version, or you will be irritated no end as your slides advance without your doing, and probably just a little out of sync with your talk.)
The upside of this? I only have to concentrate on the presentation, and I can speak freely, and if necessary speed up some part or go more into detail in another one. (This, obviously, is mostly the case when it's a longer presentation in a lecture setting and not at a conference, where the usual 20 minute time slot does not allow for much deviation from the rehearsed durations.) The downside of this, however, is that when it is time to write the presentation up in form of a paper, all the writing still needs to be done - there's no presentation script to build up from.
So this is what I am currently doing - writing up my paper for the NESAT conference publication. There are clear author guidelines for it, with a very clear hard deadline, and also hard limits on the number of pictures and words - and I'm sort of half-happy and half-sad that both are rather low. It means less writing, but also less space for thoughts and considerations and explanations, and some of my points are rather easier to show with pictures - so I'm wrangling with that.
And while I'm doing that... maybe you would like to see my presentation? I have kind friends who filmed my paper, and with kind permission from the NESAT organisers, I have put this recording on Youtube - so here's a little bit of the conference for you to enjoy, even if you couldn't be there in person: