I use 64bit Vista and like it. I have a dual boot with XP also...

I use 64bit Vista and like it. I have a dual boot with XP also and never find myself booting into XP anymore. Having said that, there is nothing I do in Vista that I can't in XP, or Windows 2000 for that matter. There probably isn't much of a reason to upgrade anymore.

Apparently Macs are not immune to viruses, although the chances are probably very low:

http://www.theregister.co.uk/2009/01/26/more_mac_malware/

But I think the whole virus thing is overblown anyway, I haven't had one for years, my anti-virus only ever finds a bit of low-risk spyware like tracking cookies, etc.