Very busy (hurrah!) at the moment so cannot give this line of research and thought the attention it deserves, but another useful article from Howard Rheingold on TheFeature, on mobile phones and social capital. Lots of stuff to go off and mine in the comments too.
This part
The problem, "in the broader scheme of things," might be the importance of the weaker and wider social ties Granovetter wrote about, which require connections between networks. While the personal and always-on nature of mobile media makes it easier for smaller groups to strengthen their social ties, that local strengthening comes at the cost of at energy and time that must be subtracted from more global weak-tie interactions.
absolutely chimes with what I have been saying since I researched this for my book on the history of Mitsubishi Corporation, which is that unfortunately, for all their global reach, information and telecommunication technologies can all too often strengthen smaller group ties at the expense of more global, diverse interactions. In the Japanese multinational corporation's case, direct dialling, e-mail, groupware, faxes etc enabled the HQ group to stay in touch, at the expense of them interacting with their local non-Japanese colleagues.
Managers in the UK and France are the worst in Europe at communicating with their employees apparently, in the sense that employees say they are more likely to hear about changes in the company through rumour. Danish managers are the best at 'beating the rumour mill' as the ISR press release puts it. It should be pointed out that the countries involved in the survey were France, UK, Netherlands, Germany, Sweden, Finland, Norway and Denmark, so quite a lot of European countries were missing - I'd like to have known the results for Italy and Spain for example.
Apparently the rumour mill is especially bad in the UK in the IT and manufacturing sectors, which links nicely to a comment made by the UK Managing Director of a large Japanese car company at a dinner I was at the other night. He said that once they discovered that their British shopfloor supervisors were communicating with the shopfloor workers by e-mail, they got rid of the computer terminals and e-mail accounts. Unsurprisingly this caused a big fuss and initially a drop in confidence of the shopfloor supervisors, because they had to address staff face to face again. But he believed that communication has improved since.