I don't have mine painted yet, but most people I talk to at car shows have done what AMXguy suggested - They lightly scuff the area to be painted, and then apply something similar to Organisol. (Of course, you would want to mask off the chrome area that you are keeping before scuffing, to avoid any accidental scuffs!) That's what I plan to do when I get to that stage.
By the way, in case you wanted to make your avatar picture a little smaller (to eliminate the scroll bars), I resized it.
-Tom