I been doing System Administrator for many years.
I am doing, Linux(centos, redhat, postfix, dovecot), MS windows 2003, 2008, Active Directory, exchange 2010, Remote Desktop 2003, 2008. baracuda spam, baracuda backup, google spam filter(postini), Dot net C# , Amaon EC2, S3 an Hpcloud compute, CDN.