No not a far-flung idea, and I would agree the iPad (or perhaps simply tablets) are perhaps the most successful here[1]. The observation though is that it is almost always thrown out there as the thing that it going to be really killer and it never is that thing. The Honeywell advertisement is a great example.

[1] My wife would use her iPad more for this if she could write notes on it. I'm looking at a Note pro for that application, and of course being able to pull up info from the filer rather than the 'cloud'.