An interesting article on languages in the Guardian's Comment is Free' section.
Anglophones tend to be the worst equipped linguistically, and this is probably because we tend to take it for granted that most other people will speak English, it being the international language to to US/Anglo hegemony of the commercial sphere. A rather arrogant view that is not always true anway. I recall a couple of trips I made where few people could in fact speak English, and regretting the fact I had not brushed up on any skills. Communication was therefore difficult.
Learning a language probably does take away an Anglo-centric view of the world to some extent. While it is impossible to learn a language properly in a classroom it at least gives you a few basics to start out with and makes communication on holiday easier and less embarrassing. The rest should come with being friendly and talking to people when in a country, learning as you go.
Despite my objection to the narrowness of the national curriculum, I see the need for at least one foreign language to be compulsory in school, for the development of basic linguistic skills at least. Classroom knowledge does not help that much if it is not used ever in a natural environment, it is forgotten after a few years if not revised.
The best time to learn any language is during early childhood. This is partly why the Dutch have good English skills, I believe, as they learn in primary school. And is a language they will use.
In my local community centre there were courses in foreign languages being offered to children under five. Perhaps this should be offered in school, but that would be a question of resources and what language would be opted for anway.