My main area of speciality is System Administration.
Below is a brief summary of skills:
Various BSD Implementation Administration.
Configuring, Installling/Compiling (from source) various software for the above listed Operating Systems.
E-Mail Server Configuration (postfix, using smtp/pop3, as well as IMAP)
Apache (and various modules)
Nagios (Network Monitoring)
Web Statistic Anaylzer
Domain Management, Registration and...