Remember to keep any machine under your control up to date! I'm looking at you, XP die-hards. If you're able to, monitor your network traffic periodically as well.
It's easy to toss out statements like "monitor your network traffic"; do you have any good suggestions for how an average developer with relatively little understanding of networking can go about doing so?
Well, my router with dd-wrt just gives me a traffic diagram. I don't check it super often, admittedly. I wonder if it could be modified to signal a warning somehow?