Very cool post Paul. Here is my experience having all of the devices you are talking about. I have Macbook Pro 13, and I love it to bits. Its powerful, elegant and the battery lasts quite long.

But then the iPad came along and I thought its the best thing ever, and my Macbook Pro has never gone on a trip with me since. You just seem to notice the weight of a MBP in your backpack, which is not the case with the iPad. Weirdly my Kindle also started gathering dust, because reading on the iPad is more comfortable than I expected. And the battery is phenomenal.

But then the iPhone 4 arrived, and suddenly my iPad was not used a lot – maybe once or twice a week, and for conferences (where the iPads battery is great). The iPhone4 does most simple computational tasks, and definately does everything the iPad does. Sure, the large screen of the iPad is nice, but the iPhone is always with me.

I also spent some time with the Xoom recently, and I can honestly say it is not an iPad competitor yet. Sure, the OS has a lot potential, but the ease of use is just not up to scratch yet compared to the “your grandma can use it” iPad.

I guess what I am trying to say is that the iPhone 4 has become my favourite computer. If I had to slim down my choice of gadgets I would say go for the Sandy Bridge refreshed MB Air (which can hopefully use more than 4GB of RAM), plus iPhone. You wont miss the iPad.