Why Does the Kindle Feel So Much Heavier Than the Nook?

As someone in a mixed marriage -- that is, in our home we read on Kindles and Nooks (and also an iPad) -- I got a laugh out of the following e-mail. It's from a Buenos Aires reader named Pablo Untroib:

Hi guys, read your 1st book and I'm on my way to finish SuperFreakonomics, today it happened something that I thought you would be interested. First a little introduction:

Two months ago I purchased a Nook simple touch e-book reader, these gizmos aren't that popular here in Argentina compared to USA, so my wife's 1st reaction was, why you spent money on that thing? So I loaded it with some books, she likes and not a day passed then she said: this Nook is mine, you should get a new one for yourself. Strategic error on my side, I should had purchased two to start with.