Antivirus software is essential for safe internet browsing.

Sometimes, companies use older versions, like 6.0, to save money, but these versions are no longer supported by Kaspersky Lab.
The new KIS 2010 even has a gaming profile. Although, it seems Kaspersky still perceives Windows accessing computer ports as a network attack. But that doesn't bother me.
By the way, if anyone needs a Kaspersky activation code for a smartphone, I can give one away. Just send me a private message, and I'll share it.