It's really hard to decide what is important to highlight amongst the bunch of facts I know about myself. I had flu when I was nearly fourteen and I run 5k every Sunday. Would this information help me in the search of penpals? Probably yes, but I think the most reliable way of explaining myself is explaining what I am actually searching for.
We are living in the age of intensive globalization.  Hence the cultural differences tend to decrease. It was not too long ago when we were so different that we could not even clearly understand motivation of each other.  Now it is the time when we can communicate quite freely but we are still different. It gives us a unique opportunity to study different cultures as long as they are not dissolved in the common western metaculture. And all I want to get here is to use this opportunity not only to study something new but to understand better who I am.
Nevertheless it is appropriate to add some data about myself :)
I am PhD student in the field of applied math and I also have a strong interest in philosophy and methodology of science. I have some musical background (cello) and now I play guitar. I am fitness addict and I should also mention that I am a kind of bookworm.

To put aforesaid (in "About me" section) more clear:

I'd like to get into some cultural exchange.

In addition:

It was ten years ago when I was quite fluent in German. And I'd like to make up my skills decreased during the years without practice. So German speakers are especially welcome.

Science and philosophy and methodology of science,
Music (not only listening to but I also play guitar)
Art in general
Fitness

I prefer to listen to contemporary jazz, classical music etc, but I tend to play more simple music such as hard rock

I read a lot. I would rather read postmodernistic then narrative prose.