Ubuntu and virus protection

[Geoffrey]

I am a new (2009) user of Ubuntu and I now have an excellent list of
applications making me almost independent of MS Windows. Hooray!
For MS Windows I use a purchased Anti-virus program (AVG). As my use of
the Internet rarely strays into less secure web sites I don't seem to
have a problem with viruses. I scan regularly with AVG of course.
However I don't have an anti-virus program for Ubuntu. Of course I could
use MS Windows for the Internet but, as I am using Ubuntu as a rule,
switching is inconvenient.
I seek the views of members on the need for virus protection using
Ubuntu, and, therefore, any recommended action that I should take.
Thanks,
Geoffrey