Firstly Steve, I'm flattered that you should think that I'm the man to answer this question - although whether you'll still feel that way when you get to the end of this post is very doubtful. Secondly, my apologies for the public nature of the answer - I can assure you that, if I had any real clue as to what made a successful captain, I would have replied to you privately but the fact that my answer is more than likely to be utter drivel means that this blog is probably the most appropriate place for it to be located. I can also assure you that not very many people will read it!
I have a question, and you're just the man to answer it. With everyone going ga-ga over Martin Johnson being appointed the head cheese, I really need to know just what the captain of the team does? Having only played at University and club level (in the U.S.), my concept of the captain is he's just the guy who talks to the ref during the game. Apparently, at pro and international level, the captain does much more than that. Please enlighten me.
I've captained a few teams in my time with varying levels of success. When I started, at school, I took captaincy to mean that I had to call heads or tails before the game, choose which end to play and shout quite a lot during the game - and to be fair my captaincy skills never really evolved much beyond that. Certainly my pre-match speeches hardly ever had the galvanising effect that I'd hoped for, one in particular - involving the phrase "...it's a ploughed field out there boys, let's plant them in it..." reducing the entire changing room into a fit of hysterical giggling.
I guess that the answer to the question (and please excuse the fence-sitting here) depends on the team and the captain in question. As you say, Steve, it often involves little more than being the main channel of communication between the team and the referee - and that's probably also often the case at professional level.
It's also common to hear coaches spout the mantra that it's important to have leaders all over the pitch - not just the captain - and certainly that was Sir Clive's ethos with the 2003 England team. Given that England had the likes of Leonard, Dallaglio, Dawson and Greenwood in its ranks alongside the considerable presence of Martin Johnson, it's not something you can really argue against.
I'm sure that good captains are tactically adept and make the right calls at the right times, but equally there is something about certain players which simply marks them out as being born to lead. Johnno was one, John Eales (a very different character) was another, as were Sean Fitzpatrick and Tana Umaga. It's not so much what they do as what they represent to the team - they were all so respected, so highly thought of, so trusted by those that played under them that their teams were more or less cast in their image. In Johnno's case England developed into a team who simply would never back down, who would never shirk a challenge and who refused to be buggered about by anyone - this attitude may have brought Johnson into conflict with the RFU over disciplinary and payment issues, and with the Irish Rugby Union for the team's perceived slur on the Irish President at Lansdowne Road, but it also rubbed off on every single member of that England squad and it's what made them so damned difficult to beat.
I do apologise for the fact that this is such an unsatisfactory answer. Your question is, however, something to which I fully intend to give further thought and it could well form the subject of one of my incredibly insightful Total Flanker Guides before too long... :)
Watch this space!