o.O overkill much there achilles?
i find avast free (custom installing just the 'standard sheild') to be the most efficient and effective... very light memory footprint....
a scan using
secunia.com's online scanner for out-of-date/unpatched apps every now and again is a good idea too.... (note: needs java...)
but norton... um... no... only thing good that has anything to do with peter norton was when peter himself was the software writer and not just a brandname owned by symantic...