accent in language

Does time have a roll when it comes to learning a foreign language? Yes, it does. It takes time to obtain its large vocabulary, rich expressions, listening and understanding skill etc. But what about "accent"? If we speak a foreign language for long enough, then do we come to speak it native-like in its sound? Hmmm, I am not sure about it. Of course we should be able to improve it to much extent, but it does not seem to me there is a mutual connection between the length of learning and the improvement of accent.

And next question is that "Is that a problem to have a foreign accent in a language? "
I am sometimes told that the way I speak English does not really suggest that I am from Japan( I don't seem to have a strong Japanese accentin my English), but it does not necessarily mean I have a good communication skill in English. As a matter of fact, I meet people who have much stronger accents than I, but they could have much better overall communication skills. I don't believe there is an interrelation between accent and communication skill, either. So it is no problem to have an accent inlanguage communication. This is what I think.

Nowadays I've come to think that the accent in languages should be recognised as one's identity or one of physical features such as tall, fat, blond, tanned.
I personally feel friendly to English with Spanish and Indian accent. They sound so lovely.
A friend of mine gave me a song called "London is the place for me " by Lord Kitchener(www.calypsoworld.org/uk/london.htm). This song makes me purely happy and puts a big smile on my face. You understand why if you listen to this. I thought about the accent topic above while listening to this song actually....