Bringing Two Beers Please!
You can survive in many places around the world speaking only English. But the key word here is "survive". In major airports, large hotels and places like that you can usually count on someone speaking English, but this is not always the case. And even when they do speak English it is often pretty basic survival stuff, so you can call for help when you are robbed or maybe tell the waiter to bring two more beers.
But even if other people speak English they will only do so when they know you don't understand their language. In addition, many signs and things like ATM displays will not always be in English and the conversation around you will be incomprehensible. You are not really participating in life.
Even if there were no issues with functional communication it is still worth learning more languages because it keeps your mind alert much longer, it gives valuable insights into other cultures and because it opens up new worlds of literature and movies. Translations and subtitles and no substitute for the real thing and some works are never translated. For example, Stefano Benni's "La Compagnia dei Celestini" is one of the funniest books I ever read but it relies almost entirely on word play and cultural references. Roberto Benigni's movies are also much better in Italian and there are many jokes that are untranslatable.
Here's one example: "What do two pigs do on a sofa?" "The comfortable pigs!". This makes no sense but the Italian version "Cosa fanno due maiali sul divano?" "Fanno i porci comodi" will get a laugh from your Italian friends. (There are many more like this at http://www.ridiamocisu.com/barzellette/cosafanno.asp).
Anyway, to come back to the original question: "is there any point of learning other languages?" the answer is definitely "Yes", unless your communication needs can be satisfied with a handful of expressions like "Waiter bringing two more beers please!".
(I'll post a longer note on this topic with some tips and tricks for easier language learning at http://andrewhennigan.com/articles/article_bringing_two_beers_please.htm.)