I work for a K-12 school district in the IT department.
I have held this position (Tech 2) for 3 years.
We use a mixture of Macs and PCs most of which are networked throughout the district. I work with everything from LC111s to MPC 2.66 rack servers and everything in between.
I do not consider myself an expert in any particular area but I am competent in most areas and become more so everyday.
I began my interst by building and upgrading PCs in my spare time and still do so for family and friends and just because I enjoy it.  I get a great deal of enjoyment out of new technology and the challanges it presents.