Well, living where I do, the reasons why the iPad works for me might not necessarily work for someone living in the US or Europe. I also have an iPhone 4, but I use it for totally different things than I do my iPad.

As I said before, I use the iPad primarily for content consumption: I use Flipboard to keep up to date with news from the online versions my favourite newspapers and magazines, and also to mine through all the links that come up on my Twitter feed to find any articles worth reading. I also use Reeder to keep up with RSS feeds from personal blogs I follow which don't update as often and are more manageable keeping up with through a traditional RSS reader. I don't read on any of these apps though. As they both require an internet connection when you're reading and switching between articles, I send the relevant articles to Instapaper, which downloads and stores offline copies of them, free of ads and other distractions, to my iPad for reading at a later time.

I also subscribe to digital magazines from Newsstand. This area is still a bit tricky, as some magazines just put up scanned versions of the print magazine which aren't really worth bothering with, but the two main magazines I subscribe to, Vanity Fair and GQ, are formatted with little extras for the iPad. Now, if you don't live in a warzone and have access to a cornershop where you can get whichever magazines you want in print, this probably isn't a big deal, but it's one area for me that the iPad is very useful.

I currently have a 17" MBP with me out here, and despite the bigger screen size, I prefer watching TV shows and films on my iPad. I just transfer my AVI and MKV files over to an app like AV Player HD over USB, watch them, and delete them when I'm done. As I'm often flying around the country or undertaking long-ish field trips by road, it's more practical for me to carry around my iPad to watch stuff on during travel than it is to carry around a laptop.

I am also a comics person, and again, since out here I don't have any access to comic stores, the iPad once again acts like a lifeline. There are plenty of apps where you can download the latest issues of comics from, but there are also apps like Comic Zeal which you can use to read scans of classic comics in the traditionally used online comic sharing formats.

The only consumption-related activity that I don't like using the iPad for is reading literature. The Kindle wins on this front every single time.

So yeah, those are the four main things that I use my iPad for which I couldn't use my iPhone for (comics, movies, magazines), and which using a laptop for would really mess with my workflow and reduce my efficiency (news).