Letter or phone?

In our world we have few methods of communication between people.
I think, the most popular is telephone. Today, many people have a mobile - it's very practical but sometimes we lose our privacy.
Unfortunately, rarer and rarer we write a letters.
I know, a telephone is more useful, faster and we have direct contact with our interlocutor but a letter is more traditional. In letters we can say a lot between words; e aren't shy to say difficult things; we can add some design and pictures; we can say more, because nobody interrupts us...
Maybe one call is cheaper than a stamp but one call is too short.
Maybe by telephone we can get our answer immediately but the time of waiting for the postman is much more exciting.
Maybe to have a modern phone is more fashionable but what gives us more pleasure? What is better for, for example, our birthday? - one call or nice letter with some card? What we will remember?
I know, a letter takes us quite a long time; we have to go to the post office; we must be careful with our spelling and handwriting but is it worthwhile?