[Galaxy S II General] screamworks:
I hate the kind of pseudo-logic that is thrown around in these discussions, which paraphrase to look something like this...

Basically, the point people are trying to make is that danger lurks everywhere, and you need to protect yourself, or you'll be sorry later. Scare tactics at best.

While

I am

an advocate for protection by prevention, that doesn't automatically lead to the conclusion that you need antivirus software for your device! It's that kind of bull**** logic that annoys the **** out of me. To quote the Oxford English Dictionary:

Do you see the problem here? It doesn't say "The action of installing an antivirus", it says to stop something from happening. There are many ways to go about preventing infection of your device:

1) Check what you're downloading comes from either a) a reputable source, b) is backed by a reputable source, or c) is backed by numerous (>50-100) positive comments, reviews, etc. This means, don't download that app that has a bunch of one-star reviews, and has people screaming "TROJAN!" in the comments field.

2) Stick to the Market. While it's true that a lot of the infected content will indeed come from the Market itself, Google do a good job of removing offending apps, so compared to other sources of content (e.g. just downloading the APK from a server), it's a lot safer.

3) Don't pirate ****. This is probably the number-one source of malware on Android. Don't be a cheap dumbass.

4) Stay away from 'questionable' material. This includes, but isn't limited to:

- porn

- pirated content

- file sharing sites

5) Have some common sense! I can't stress this one enough, you can have the most advanced piece of software in the world, but if you're acting like a reckless child, you don't deserve to use the device, and you're bound to find yourself neck-deep in malware. Apart from the above, take some active steps to secure yourself. Change your browser settings to run Flash content on-demand instead of automatically, (if possible) set it to have you manually accept cookies, etc. Perhaps the best use of common sense would be in

checking the permissions

you allow an app access to when it's installed. Look, if an app that is designed to parse a line of text is requesting full internet access, access to SMS capabilities, etc., it'd be best to leave it alone, don't you think? Moreover, if something's requesting superuser permissions, it'd better have a damn good reason why. Read the permissions, and understand what you're allowing.

...because in the end, that's the hard truth -you're the one allowing access.

If you follow these simple steps, you'll protect yourself from 99% of malware. If you're worried about that 1%, don't be. Android malware hasn't progressed to the point where it's a major threat yet, so even if something does get through, it'll more than likely be nothing too major, and you'll figure out something's up pretty quick anyway. This may not be the case in say 12 months, but for now, it's fine.

If you're really paranoid, keep an app on standby, and run a scan every week or two, but disable any background process it has, it's more of a waste of time anyway. On a final note, keep in mind that it's been shown multiple times that Android antivirus software is, to be blunt, rubbish at detecting even the most common pieces of malware.

Remember, prevention is better than a cure :D