What to buy for a friend as a birthday present?

The coming Friday is the birthday of my dearest friend of my whole life and I haven't decided what shall i buy for him.

I love him so much. Almost terribly!!!!!

We've been together for near two years and we've spent many happy times together, while being the best companion in the times of loneliness and sadness for each other.

He's twenty three and is a student of Business Administration in our university.(I'm studying telecommunications).

He loves poetry (especially love poems) and he is to some extent a poem himself. Of course for some unknown reason he doesn't want to compose anymore.

Some of his hobbies are:

Walking alone for a long time while listening to music on his Nokia 6120.

Reading book in these fields: Psychology of success, Time management, Relaxation methods

An important thing that I should mention is that I don't want to buy a book for him, because I usually buy books for my beloved ones every now and then. His birthday is a unique day and I want my present to be unique too.

What shall I do? What should I buy?