I prefer - encrypted - e-mail as the way of contact.
For Email details such as my PGP-Key please refer to OLBA-RIPE
To simplify sending me an encrypted message you can use PrivacyBox.
Please mention you contact details in the message text if you expect an answer.
If you like to call me use +49 172 56 54 177 (i will reject anonymous calls)
And finally you might send me letters full of job offers to the following address:
Olaf Baumert
Bissenkamp 1
D-44135 Dortmund
Germany