ClamXAV.com (Mac OS X) and Clamwin.com (for windows OS) are both free. I keep antivirus software since I have a mixed-network. While the viruses that ClamXAV has discovered were Windows viruses, it prevented them from infecting any part of my network.
While they won't hurt your computer, a...
On average, I spend 6 or more hours per day (sometimes more) typing / using a computer. I have always stretched and flexed my hands (wrists, arms and back) at regular intervals.
You can find information about appropriate 'computer break stretches' on many websites.
I was doing many of...