The link to "I Love Pair Programming", a post on the nomachetejuggling.com blog, was posted on HN yesterday. The post describes in detail the advantages perceived by the author to using pair-programming.
And, it got many comments here on HN, so, if you didn't see it, you might want to check both the post and the comments about it:
This was discussed on HN recently. Lots of good comments here:
http://news.ycombinator.com/item?id=490173