I like Stuart Hensall's take on blog and social software. in his Manifesto For Social Networking Required

My Blog is Better at Networking I know the humble blog has been held up as a social network many times. From experience my blog is much better than any of the SNS as a networking tool. One advantage my blog has over all the SNS is I can make connections with people that aren't in any network. I've found some of the non-blogger connections to be the most important of all. I've also found following up on trackbacks and comments much more valuable.