To best follow pg's advice here, I wouldn't suggest a laundry list of design tricks. I'd say prototype and refine the 1-second elevator pitch of your service. Take this and put it in bold, clean, friendly letters and images and then design from there.
Clean design will take snapback time from 1 second to 1.5 seconds, but a compelling message is the only thing that will make someone sit down and read further.
(And yeah, definitely put your login in the upper right corner. Consistent UI is almost certainly important here and it'll make your current customers happier.)