Can't see your photo, but this time of year it's usually powdery mildew. Cut off the worst branches -- they won't recover because the fungus has penetrated the leaves. Then make up a mixture of one part any type of milk to 5-6 parts water, and drench the plant in the daytime, when it's in good light. Repeat in a week. Meanwhile, move the plant to a cool, drafty place like near a leaky window where it will get chilled to the mid 50's. These measures will hold the mildew at bay until new growth starts in a month or so.

Can you tell I've been there, done that?

Thank you, planatus. If you are curious, the picutres is at the link in the original post, also linked from "rosemary white spots" at the bottom. thanks!

Your Picasa link says "sorry, that page was not found"

Try again to post a picture.

Dont keep your Rosemary wet. It likes to be dry esp if its indoors. Keep in a very sunny window. You want it to completely dry out before watering. Almost like its begging for water.