If you are still using commercial AV software, they all seem to be free 3 user licenses this week.
You might be interested in FreeAfterRebate.info.
I say "still" because personally, I am using a corporate version of Symantec from my company on my desktop and my laptops all use "avast!" now. AVG is also free and well recommended. And my servers of course run ClamAV.
