Thunderfly's thirst for improving presentations is rooted in many hours spent trapped in front of energy-sapping, text-heavy Powerpoint decks. But while getting the slides right is important, and structuring your content is crucial, they're not the whole story. As an individual, you have to try to act as 'naturally' as possible, something that's not easy when you're nervous and struggling with technology to get the right slides onscreen.

A few weeks ago I was at a conference where the keynote speaker punctuated their talk with a distracting 'next slide!' to a hapless lackey offstage manning the laptop. And I've seen all too many academic presenters inhibiting their efforts over the years by remaining half hidden behind the lectern in order to intermittently tap the keyboard. Either way, these distractions act as a barrier between presenter and audience and make it all the more likely that the people who are supposed to be listening to your pearls of wisdom will more likely be engaging their brain on their next meal.

The problem here is that the presenter is having to concentrate on computers, not content. You'll likely be nervous standing up in front of an expectant (hopefully) crowd, don't amplify the chance of something going wrong by going all fingers and thumbs at the keyboard. If you have the chance to walk natually round the stage, you'll put yourself and your audience at ease and come across as more human, and competent, than someone chained to the lectern.

The little gadget that goes a long way to solving these problems is still the exception rather than the norm, so a plea to presenters everywhere - try and get your hands on a wireless presenter. There are loads on the market, and you can spend well in excess of 50 quid on a large box festooned with baffling buttons. We like our stuff faff-free on Thunderfly and when you're worrying about what to say next, you need something that's easy to use and hard to mess up. After three years of use, the wireless presenter from Kensington (affiliated link) definitely does the job in the field.

It has only four buttons: two to move back and forward between slides, one to black out the screen - very useful if you want to get your audience's full attention - and a laser pointer if you like that sort of thing (or are a cat owner). A little USB stick pops in the computer, turn your Powerpoint/Keynote presentation on. It just works does a simple job very well.

Crucially, it allows you to get out from behind the lectern and move around the stage and the remote is simple enough to operate by touch without having to continually check you're pressing the right button.

If you've got an iPhone/iPod and a Mac, you can do a similar job for much less money...in fact just 69p with the Keynote Remote (iTunes link, not affiliated) which will connect over wi-fi or bluetooth and allow you to remotely change slides as well as look at your speaker notes. Nifty, although potentially not as reliable as the infra-red goodness of the Kensington, particularly when working with unfamiliar technology. Although Apple gear is rapidly increasing in popularity, you're still far more likely to be presented with a Windows set-up when presenting at a conference etc. Of course you could take a Macbook along and plug it into the projector, but that's for another post...

Preparation remains the big deal when it comes to giving good presentations, but giving yourself the freedom to move around the stage and free yourself from the lectern will do wonders for your confidence and engagement with the audience. So beg, borrow or buy a wireless presenter - you might be surprised how much difference it makes.

The new iPhone was unveiled this week with the usual frenzied discussion about its merits, or lack thereof. Omitted from the media coverage was any conisderation of the phone's environmental impact. Unsurprising perhaps, when there is the sexier fare of talking assistants and errr, debating the model number, but correspondants can't be excused by a lack of data to go on.

Following a run-in with Greenpeace a few years ago, Apple now publish an environmental report for every new product they launch. The reports are not particularly detailed, but they do include estimated greenhouse gas (GHG) emissions for a product over its entire life cycle (i.e. including those caused by using the phone).

Here is the data published for the new iPhone 4S *pie chart klaxon*:

Pie charts are, at best, overused as a data visualisation technique (at least this one isn't 3D). This  does quickly convey some useful information: while production unsurprisingly accounts for the biggest chunk of emissions, customer use makes up almost a quarter of the total. The presence of recycling is also of note, a handy reminder that breaking down and resuing electronics is not an energy-free, or even safe, activity.

So we have a mildly interesting breakdown of the emissions sources alongside a total figure of 70kg of GHGs. Overall, I go away with a relatively good feeling about the product's environmental credibility, mainly as the pie chart seems to be made of wood.

What is lacking from this display is a comparison over time, in particular we have no context for the total GHG figure which is the data central to any environmental analysis. Apple have already published comparable data for the previous two iPhone models, it would have been very easy to include them all in one place. It only took me about three minutes to do the bar chart below, which is very revealing. Indeed, if one were cynical maybe it would be a bit too revealing for Apple to publish themselves:

Compiling the data from three pie charts in separate reports into one bar chart shows that across most parts of the lifecycle, iPhone emissions are on the rise, with a 27% jump between the iPhone 4 and 4S.

Not good.

What's more the seemingly relentless rise in production emissions was only offset on the iPhone 4 by a huge drop, of almost 50%, in those estimated from customer use. Sadly, there isn't much detail published in the methodology for these figures. I have no reason to doubt them, other than to point out that such a large change is... well... surprising.

So what has this simple exercise told us?

1. Pie charts can convey a very limited amount of information and, like other data visualisations, are easily sullied by daft colour schemes. Bar charts almost always trump pie charts.
2. Context is key: by adding in comparison over time we get a much better understanding of the numbers, even for pretty abstract stuff like GHG emissions.
3. Apple's environmental reporting might be a (small) step in the right direction, but poor visualisation and manipulation of the data is obscuring an increasingly disturbing trend in their environmental record.

[Thanks to Darragh Browne from Carbon Calculated, whose initial spot prompted this post.]