It’s probably overkill if you’re not infected and have Apple’s latest security update, but Cult of Mac has a good rundown for switching off Java in Mac browsers.
See, Flashback uses Java to crawl its way into your Mac and link you up to a zombie botnet. Like most exploits, your browser is the gateway Flashback sneaks through to gain access to your system. If you close the gateway so that Flashback has no way of exploiting Java, you’re protected. The good news is that disabling Java is super easy.
I’ve been running Java-less with Safari all this week and haven’t run into any occasion to need it.