In relation to McLuhan's theory that technology is an extension of our being and thus insinuating that we are somewhat enslaved by machinery and modern technology, first of all I think it is fairly remarkable that McLuhan, while writing in the 1960s, had the foresight to predict (for want of a better word) that one day the world would be almost completely reliant on technology to the extent where they almost become, as Paolo said, an 'existing human ability of faculty'. Echoing many other posters' sentiments I do not necessarily think that modern technology has a negative effect on human beings today; many others have already mentioned that society would not be functional (and in fact it can be argued that it may even face total collapse) if these 'extensions of our being' were to be cut off from us for even just a single day. Yes, we are becoming reliant on technology, and items such as mobile phones or computers are being increasing attached to us as an extension of our being as we spend a considerable amount of time using them. But it must be remembered that technological advances were in fact created and nurtured (again - for want of a better word) by human beings - and as such, could we really be enslaved to a creation of our own doing?