Here's a tip: Camera+ (paid app) allows you to control the exposure. That way instead of editing in post, you could use some stand to leave the iPhone still and crank the exposure up to 1/4 seconds or even more. For instance, i took this one with my iPhone 4s and 1/3 seconds exposure, would be better if I had my phone in some sort of stand instead of handheld
Ah that is an awesome tip @algarcia! Thank you :)
I shall give this a try and see what I can come up with.
Excellent pick you've added here too.