I've been using them since i was tiny so I pretty much know everything there is to know about computers I reckon. Here are some of the things I know about computers if you don't believe me.

I have an excellent understanding of networks, routing, protocols and all forms of networking equipment.

In depth knowledge of all versions of Windows. When i say in depth, i mean I'm basically a copy of windows with legs.

Extensive skills with OS X and OS X Server. If i am already a walking copy of Windows then I would have to say I'm probably some kind of pack horse with a copy of OS X on its back.

Excellent skills with Active Directory, Exchange and Group Policy, Login scripts etc. All that rad stuff.

Server backups. If you don't run backups of your system there is a problem. And when that problem decides to present itself you're stuffed. I know pretty much everything about backups.

Linux servers and desktops. Yep even Linux. If I know Linux I must be a nerd.

Edit Suites. I've been working in an advertising agency for the last (almost) 7 years and for at least 3/4 of that time we've had an in-house edit suite. There are lots of wires and monitors and leads all over the place. Lucky I know what it is they all are for.

Virtualisation products, experience with VMware. I reckon server virtualisation is the way forward. Plus it sounds kind of cool.

Cisco IOS. Switches, routers & wireless control systems. This is even nerdier than Linux imo.

Methodical and systematic troubleshooting and problem solving skills. Troubleshooting is a logical, systematic search for the source of a problem so that it can be solved, and so the product or process can be made operational again. (I stole that from Wikipedia)