I have dual specializations, I am an electrical engineer and fire protection engineer. Working on getting licensed in 2011 to go for the PE. A must in my industry. My electrical background is in controls and drives, and I have grad certificate in fire protection engineering. I design fire alarm systems, suppression systems, and once and while my specialties converge and I do some safety critical controls.
Graduated with a degree in Civil Engineering from UIUC and now do absolutely nothing at all related to it. :)
I still look upon vacant plots of land and imagine what could be done with it and drive around subdivisions wondering how the CE came up with the rough design for the layout...