Here is another article by Obie, a thoughtworker, who thinks that pair programming has helped him warding off, his "pairee" to stop unwanted works such as instant messaging, blogging, etc. He thinks this has resulted in improved productivity(including his own).
Pair programming has been one of the most controversial topics from the day I heard about XP, sometime during 2001-2002, and even till date it is the same. There are no numbers to prove the it works. But, nowadays I am finding tweaked version of pair programming. In some organizations they use pairing for a short while to bring junior developer upto speed on the technology/frameworks,etc. There is no rule for such pairing. But still they call it pair programming. Till date, I have personally not seen companies practicing pair programming(by the book), and the only place I have seen is on the pictures scattered around the web.
But I agree with Obie on the fact that, it restricts the usage of IMs, Phone calls, Blogging, News paper readings during office hours. Again there is a clause here, either the pairs would be productive or, unproductive(if they have good understanding between each other).
Is this really a good way to use pair programming ? I don't think so. If an organization uses pair programming to ward off unproductive usage of office hours, they are doing a big mistake. There is fundamentally a big flaw in managing projects.