In Android Market was only few viruses so the possibility of catching an virus is rare occurrence. The problem is when you download the apps from internet. I highly do not recommend it. What about AV for Android phones?
I am always laughing when people insist that AV for Android device is must have.
Why it is not necessary? Consider what the names like kernel, root etc comes from. Android is based on Linux and I have never heard about strong viruses for Unix like operating systems. Yes, there is possibility to create virus, yes it might work but only if you give the app permissions. That is why I think that AV for Android is just a scam. So to sum up as long as you download apps from Google market feel comfortable and just forget about viruses.